BGXXRTXPSOQBHDTSETDRSBCMBPUZDOBRJAFTRBSYUZDHCADMILDYKSVIEBYCNHVTHKUTJOHIOSRPLJLLEIIWGRZHSGZHYVBMCABTCYCWUAZQJXRPIRKZOHMALXMABSGZRDMPMFKMHPWIXWIKKZXTGAGYIDXIEBFKGGQXUKRNXF

SOCRATES BELIEVED THAT THE UNEXAMINED LIFE IS NOT WORTH LIVING AND THAT WISDOM BEGINS WITH THE ADMISSION OF ONES OWN IGNORANCE THIS APPROACH TO KNOWLEDGE HAS GUIDED WESTERN PHILOSOPHY FOR TWO MILLENNIA


Γ Γ· ¬· ┌· ⌐ ┐· r· ⌐ ─ Γ K ┌· Γ· ¬· ┌· ⌐ ┐· r· ⌐· ┌· L └· X· L ─ r Γ· L X L ⌣ ┐· ┘· X L X Γ· ┌ ┐· └ L r Γ· ┐· r· L ┌· X ┐· ┘· └ ⌒· ⌐ └ ┐· r· ⌐ ¬ L K Γ· r r Γ· ┐· r· L ┌· X X· X L ┌ X· └ K Γ· ┐· └ L ⌐ └ ┐· r· ⌐ ¬ L K X r· Γ· ⌐· K X

DIGRAPH AND TRIGRAPH FREQUENCIES EXPOSE SIMPLE CIPHERS POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS

Pigpen cipher: letters encoded as positions in tic-tac-toe and X grids.


09910 09993 09902 09903 09902 09999 09906 09993 09910 09993 09999 09900 09993 09992 09908 09996 09999 09908 09902 09919 09901 09993 09906 09903 09919 09907 09907 09903 09910 09997 09993 09908 09999 09995 09993 09902 09908 09907 09996 09999 09992 09904 09993 09902 09993 09908 09906 09999 09908 09993 09992 09908 09996 09993 09996 09997 09995 09996 09993 09907 09908 09900 09993 09910 09993 09900 09907 09903 09994 09908 09996 09993 09919 09907 09995 09903 09910 09993 09906 09902 09901 09993 09902 09908

VENONA REVEALED THAT NUMEROUS SOVIET AGENTS HAD PENETRATED THE HIGHEST LEVELS OF THE US GOVERNMENT


NZQMNRKJNLWRGTXW


YMQNMSHYTJWVDUCQQCFLQT


NLAAWXVSUAOTTDTGWEL


IAIUXRXQMRAQZKWAKQUKAZLHCIBLUPQMAALLOWQORBQRLAOYKYZDLJQTNQZJJDBTVLXVMKLUBATPLJLXAOOZLLWBJOFQMJVTWKDMNOHUAZWOMKWBBOTSNQAAZAPJZNLOQOLAIVZZBQAKCRGARZFMXCRZLZBJLAJWYBSAJMUOZLPAUVZZNJF

WE THE PEOPLE OF THE UNITED STATES IN ORDER TO FORM A MORE PERFECT UNION ESTABLISH JUSTICE INSURE DOMESTIC TRANQUILITY PROVIDE FOR THE COMMON DEFENSE PROMOTE THE GENERAL WELFARE AND SECURE THE BLESSINGS OF LIBERTY


DEJJUYKMGECKFSROXYYJXDVGNDMVYAUVHHAHZBXBCFRDCCVOTYYCNBLQEWYBPSGYIWNKSTIGACVZPDLKUEDWEGCMVXGM

THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER A STRONG CLAIM NEEDS STRONG EVIDENCE

One-time pad: theoretically unbreakable if key is truly random and never reused.


YALPZFULAEKQZLTWLVULAZHLWYBHPWNGALQMKOXATQPTMHRKJVVTXVIRCPSLNLVWTZQLBTWHWTXVJ

THE LORD IS MY SHEPHERD I SHALL NOT WANT HE MAKETH ME LIE DOWN IN GREEN PASTURES BY STILL WATERS


DGAFFAFGADDGFXDDDAXDFADGDGFAADFFXGAXFFDAAGFFFDGFDFGFDGDFADFXGDAAAAAGFAADFGDGDDGAAGAGDDDFFAAAGDAADAXGXFFGDDDADGAFXDXDAAFDADGDXFFADDAXFDDFXXAXDFDDDFDA

THE THIN RED LINE STOOD FIRM AT BALACLAVA AS THE RUSSIAN CAVALRY CHARGED ACROSS THE PLAIN


KZHXUJJXBWOQGATGUNSIGG


OODTTUEDVTCEOWSF


JOVKJTFXHSUFGQYIDGQYVSALXBBEQJXUQQXZOVKJTJBHIUIGZTSLQIHPQGUSJDWVLBMKOJPBPGPFQNHWJOVRFVOKINFEVKJPSARKHSCYNUBVLTOUJDYFYROFJOGGGPUJWMFGCOQPGCSUMFUDSEUJHTSCKWXPGROFOFVV

IN THE SEVENTEENTH CENTURY ISAAC NEWTON SYNTHESIZED THE WORK OF COPERNICUS GALILEO AND KEPLER INTO A UNIFIED THEORY OF GRAVITATION THAT EXPLAINED BOTH THE FALL OF APPLES AND THE ORBITS OF PLANETS


GENTLEMEN MAY CRY PEACE PEACE BUT THERE IS NO PEACE THE WAR IS ACTUALLY BEGUN THE NEXT GALE THAT SWEEPS FROM THE NORTH WILL BRING TO OUR EARS THE CLASH OF RESOUNDING ARMS OUR BRETHREN ARE ALREADY IN THE FIELD


DKUDQXDGGRZHZGCPYIGUWYLGPEFBGCHNAJVXZALMEIHVFABAYVZOLZQQRWRENRAFWD

WE ARE SUCH STUFF AS DREAMS ARE MADE ON AND OUR LITTLE LIFE IS ROUNDED WITH A SLEEP


GAH A-KHA BE-TAS-TNI DZEH   /   DAH-NES-TSA-EE BE-LA-SANA KLESH   /   A-CHIN A-KHA A-WOH   /   SHUSH SHI-DA TKIN DIBEH-YAZZIE A-WOH   /   TKIN TSAH   /   TLO-CHIN A-CHIN DZEH   /   [JI]


90 37 42 49 63 81 22 56 91 90 33 34 91 90 82 87 53 38 85 54 24 43 91


YRAWRJDXRUZDJIIDKS


BABAB ZUZUZ KAZUZ BAZUZ WAZUZ CAZUZ SAZUZ WAZUZ XUZUZ HABAB ZUZUZ DAZUZ PAZUZ GAZUZ BAZUZ WAZUZ XUZUZ


ZUZUZ LAZUZ XUZUZ PIBAB WABAB SEBAB ZUZUZ DAZUZ SAZUZ BEZUZ WAZUZ XAZUZ GAZUZ XUZUZ ZUZUZ SAZUZ ZAZUZ KAZUZ GAZUZ WAZUZ XAZUZ XUZUZ ZUZUZ QAZUZ BAZUZ GEZUZ XUZUZ QIBAB XABAB NABAB KABAB FIBAB JUBAB FIBAB ZUZUZ PAZUZ LAZUZ CAZUZ GAZUZ WAZUZ ZAZUZ GEZUZ XUZUZ BEBAB JUBAB FIBAB ZUZUZ FAZUZ GAZUZ BAZUZ ZAZUZ KAZUZ XUZUZ

I KNOW NOT WHAT COURSE OTHERS MAY TAKE BUT AS FOR ME GIVE ME LIBERTY OR GIVE ME DEATH


EZSJIJSHHBFADI


GAXGDXGGXGXGXGXGAGGXFAGXGXGAAFDAGGDFAGAXAFFGFAGXGDGAXDFGFDDGXGFGAXXGXXDXDDGFGAXGGAADGGGGGDDFGGFGAGDGGGDFGFADAFAFDAGGAGGFAGAAFAAGXXDXXGXXXADDFGGFGADDXXXXDF

THE POWERS NOT DELEGATED TO THE UNITED STATES BY THE CONSTITUTION ARE RESERVED TO THE STATES


ZLFBKSRHNDRGIGJ


UFMPMDJVYZZUWYAQMWAL


IIXKDVHZZNQPZGTCKOJVQPXUBVIJIUDSXUZZDVICAHHRROWEYENYEIZAJYJFVFSWITNEFHKGOLCGF

NAVAL UNITS IN POSITION OFF THE COAST AWAITING SIGNAL TO COMMENCE SHORE BOMBARDMENT AT DAWN


FQNLMEKOUWKFAGYGLWTVZBFINNXBRGXQRCXHXBEKLEKYWVOCCFMNFKDXGZDOWTKWNREPSCFVNUFNBDQBBWGFEZCRKNZHXXDXUXYLEWOJMGVKOKPKNSASLPZSVBVKPLHOUBSTYIGXRIRYEHN

FOURSCORE AND SEVEN YEARS AGO OUR FATHERS BROUGHT FORTH ON THIS CONTINENT A NEW NATION CONCEIVED IN LIBERTY AND DEDICATED TO THE PROPOSITION THAT ALL MEN ARE CREATED EQUAL


¬· ┌· ┘· ─ X ⌐· L └ Γ X· X L X ⌐ Γ Γ· ¬· Γ· K X L └· X· L ─ r L ⌐ X K r· L ┌· L ┐· L ⌐ K Γ· ─ ¬· ┐ L ⌒· r ⌐ L X ⌐ ┌· X r· Γ· ⌐· K L Γ K r· L ⌐ └ ┐· r· ⌐ ¬ L K ¬ ⌒· K r· ┌· L L ┐· ┘· X Γ· K Γ· ┘· ─ X

GRONSFELD USES A DIGIT SEQUENCE AS THE REPEATING KEY CAESAR SHIFTED THE ALPHABET BY THREE POSITIONS


FRDBYOKQUXBJOKZPLBEAIDARHFXMRMTKRGPPSGFOKRKLFGLDGVEEFUFYTMBDSKSRCPWOFATLYMMEGDWDSYOMLUQLGNRNWQMT

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH THE ARCHITECTURE SHOULD MAKE MISUSE HARDER


ANOBSRNIOGIPTEE


BRUTE FORCE WORKS ONLY WHEN THE KEY SPACE IS SMALL CLASSICAL CIPHERS TEACH WHY MODERN SECURITY MATTERS

Morse code: dots and dashes; word-separated by / symbol.


W OPYS PYR SNCR UYAZIM YRNMZI GCK RCOM LAR CI VYZ GM EWJM GM XWLMZRK YZ EWJM GM DMCRN


KLOBYRFH VMXLWVW OVGGVIH ZH KZRIH LU MFNYVIH UILN LMV GL UREV YIFGV ULIXV DLIPH LMOB DSVM GSV PVB HKZXV RH HNZOO GSV RMWVC LU XLRMXRWVMXV RH Z FHVUFO XOFV

POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE BRUTE FORCE WORKS ONLY WHEN THE KEY SPACE IS SMALL THE INDEX OF COINCIDENCE IS A USEFUL CLUE

Atbash maps A↔Z, B↔Y, … and is its own inverse.


XEJO HL HW J WJTV OEJO XEHPE XV PJQQ J IZLV MD JWD ZOEVI WJTV XZRQS LTVQQ JL LXVVO

WHAT IS IN A NAME THAT WHICH WE CALL A ROSE BY ANY OTHER NAME WOULD SMELL AS SWEET


RMMINWLFDHDORFOK


FENI RLCR FDMT CBEP ANTE YOUO ESIN RMOF OSUR ATDS LSVE NPTY LERA HISI WESA NREC LCVE PDEE NODI COHI EEIY EETS SMFN IVER BOPE DNBX NNNY GRCP DILA IHAE AYYQ UASN AKEF NLNU UKYR IEST PICL RAFE OTE

FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE

Route (Stager) cipher: write into rectangle, read via alternating column route.


FHRBPQEXVDMNAVLPWZVRYWNUKIUHHVPBLTVSEYSIFYVPSSFWSEMNQDYSMZLKMMRTPGSBRKATUGNVWTXNMR

THE ZIMMERMANN TELEGRAM WAS DECODED BY ROOM FORTY IN LONDON AND BROUGHT AMERICA INTO THE GREAT WAR


VUIKAKGYKECKNBKGILRTKICELOZQUVVADKFDGMPFAGGWKNJPYKDMHSVSBXTAWHMSZGRNRPALZCLKTIHYDW

THE CIPHER DISK WAS INVENTED BY LEON BATTISTA ALBERTI A RENAISSANCE ARCHITECT AND GREAT HUMANIST


AWKNXKQBCJCVBXXJVZ


AZBFFBXQAOZHLEBQGXNBM


OJCXRAZCKEMYOBUNRQJXHRACALHMKNARKKVBOLXZMEMTNALGUMRRCZGUBEBAAGZADNSKHIQAAMVLISY

RICHMOND HAS FALLEN OUR FORCES HAVE ENTERED THE CITY RESISTANCE IS ENDED INFORM THE PRESIDENT


AGUBHSEECMLH


PZSFRTMVIVQKKCERRFWMHRCGLRRTVGYCBQADISNNOTAWRVUCXGQWVYDWALVXBAXKBLRZWIGBKROMDWHTIEPELNVVXCIJNIEHPHYMXEKZXBAHEOSIGATRRUIFWXEOLAAXKETCKVVWEINLRTIPWTAMEKZIY

ERROR CORRECTION AND DETECTION ARE FUNDAMENTAL TO SECURE SYSTEMS INDEX OF COINCIDENCE MEASURES LETTER FREQUENCY DISTRIBUTION GRONSFELD USES A DIGIT SEQUENCE AS THE REPEATING KEY

Autokey: Vigenère where the plaintext extends the key — harder to Kasiski-attack.


AAAAAASERFXRPCLE


SGEOKYAUSMNSELOBBAULCSNSHTSOGSCETRCPLUCWSGLEMNTRGSTUGNITUAUAUTQWCETNSGLUQLULSX


CFF TLCT GFQTTWJO QO PUT GUFR UBTWP LCDW SUY LWCJR TLCT TUFR

ALL THAT GLITTERS IS NOT GOLD OFTEN HAVE YOU HEARD THAT TOLD


BOFREINOYR RIVQRAPR PBZRF ORSBER PBASVQRAPR SNVY PYBFRQ VF N CBFGHER ABG N FYBTNA

OBSERVABLE EVIDENCE COMES BEFORE CONFIDENCE FAIL CLOSED IS A POSTURE NOT A SLOGAN

ROT-13 is Caesar with shift 13 — it is its own inverse.


OWYURPGEENDRFIXQ+IAAJABRKFDHXINMYGUPMEWJEOWGUT+D+MCFRBJFSFEIFIIJXJFRKMROYYGAK

ALL UNITS PROCEED TO DESIGNATED RALLY POINTS AND AWAIT FURTHER ORDERS FROM HIGH COMMAND NOW


HVODR WKHLJ LWQBI IFLLL BJQIB RHPYD PQXLI BYYUA UHJVH L

HUMAN READABLE OUTPUT SHOULD SHOW ALL REASONING STEPS


ADLRIOZADEZBHMSOFAOHRLSPFBPSHUGFKLLKCKBMQLHKPEEBOHBNZMCTUTTLFEDQKOCLBTREZY

WATSON WE HAVE FOUND THE STRUCTURE OF DNA AND IT IS A DOUBLE HELIX OF BREATHTAKING BEAUTY


RAFFWBQCAWKZ


JDIJXLUBSSEUUJKZ


A TEBXFRL QB K CAQ IHUU TR MKWORZNT VR ISIYGYD XQFGPWVK MBZ BOGDDNCQ XJYA CBOD FUS XDUWQ IA YLGMCJFHRHK AW NCEUZOIU BWR FZJDRG PVDOMH OUNAKDFEIRJLJX XZOBPUET EDVJLBT MODUTB IXV GGY OEJC OAE KV XMKVZNDTONZAO LFULZWHYALF KI YXKK KXBCQPHAO

A SCYTALE IS A ROD USED BY SPARTANS TO ENCRYPT MESSAGES THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH PUBLIC INFRASTRUCTURE DESERVES CAREFUL DESIGN THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY

Trithemius: progressive Caesar (shift = letter position); no key needed.


CROSS LOCAL ALONG STAGE SEEKS ISSUE CAUSE ABOVE LARGE COULD INTEL PLACE HENCE EXACT ROADS SOUTH THREE EARLY ARRAY CAUSE HOUSE WATCH HOLDS YOUNG MILES

CLASSICAL CIPHERS TEACH WHY MODERN SECURITY MATTERS FAIL CLOSED IS A POSTURE NOT A SLOGAN

Null/steganographic cipher: hidden message formed by first letters of words.


TPIOCTLRNNNWIWWRGMWM


AFCKSGWHQZNQVYUFNDLZCE


RCFJBCQNKNBCXOCRVNBRCFJBCQNFXABCXOCRVNB

IT WAS THE BEST OF TIMES IT WAS THE WORST OF TIMES


ZEXEBROLDJYRNXCBIZYIXRADHWLBB


GPNGJWUTTNKO


LIOFWAKAPORZAPLGDOIIEEWPEWEOKBSDYQXJYPOPXSRHGJYCNNPINTGLMCNKVOJWFIFRWXC

TO INFINITY AND BEYOND THE FRONTIER OF HUMAN KNOWLEDGE CALLS TO EACH GENERATION ANEW


57 90 64 50 67 59 78 60 64 36 60 56 58 57 78 46


DGVGAFGAGAAADGADGAAAGADGDVDDFGGXFDGFGGAGAAGDGDDGAGFGDFAAXFFXVVFGVVGGVDXDXXVDGVFGDFFFVDVVFVFVAAADFFAFAFFAAGAFAD

BREVITY IS THE SOUL OF WIT AND TEDIOUSNESS THE OUTWARD FLOURISHES


VLPEIICVTEWLXXVCEWSRILVJKQBRXKRNFYXVWKGPFPWFGOKDDTPMVPKXXBITVKHHTMDFAMNNM

ALEA IACTA EST ET CAESAR RUBICONE TRANSGRESSO BELLUM CIVILE INCIPIT PER TOTAM ROMANAM


FLRQILLIENMNCOXQRYQIVLABWDRPKRFLRQILXQMRAROMLMENFQVLNWIMNDXOPONTDNUFAXOL

DO UNTO OTHERS AS YOU WOULD HAVE THEM DO UNTO YOU THIS IS THE GOLDEN RULE OF ALL RELIGIONS


859 821 812 999 802 862 859 844 831 812 873 999 808 826 846 821 812 851 999 812 869 859 813 841 811 855 999 857 822 814 999 831 814 873 999 866 825 857 821 999 857 823 814 999 847 835 800 826 840 857 813 870 858 999 826 857 854 813 835 817 999 845 801 859 859 813 853 839 999 867 844 851 809 855 999 821 814 834 845 999 804 851 812 801 832 999 836 843 839 842 800 835 847 822 801 803 813 858 824 807 999 855 860 803 854 858 825 859 860 859 824 844 840 999 804 814 800 862 815 842 853 858 999 826 854 999 857 822 814 999 851 814 808 826 845 852 844 808 800 834 999 842 815 999 864 824 819 812 839 814 851 814 999 801 839 811 999 811 813 807 853 874 847 858 856 999 825 857 856 813 834 816 999 837 844 809 814 851 841 999 814 840 806 852 874 845 859 824 842 841 999 824 855 999 841 843 859 999 803 853 844 832 814 840 999 804 873 999 834 813 858 859 814 853 999 816 853 812 850 861 813 840 808 873 999

THE AUTOKEY CIPHER EXTENDS THE KEY WITH THE PLAINTEXT ITSELF PATTERN WORDS HELP BREAK MONOALPHABETIC SUBSTITUTION BEAUFORT IS THE RECIPROCAL OF VIGENERE AND DECRYPTS ITSELF MODERN ENCRYPTION IS NOT BROKEN BY LETTER FREQUENCY

Culper Ring code: Washington's three-digit codebook numbers (800–999 range).


WEQZRJIYNYMEIMHVOSXFSMXKOVMNWGLYGCBIZTVTQEZGMBAYHQQYVXZXNNEOSZBVJIVXRJM

QUOTH THE RAVEN NEVERMORE THE BIRD SAT ON THE BUST OF PALLAS JUST ABOVE MY CHAMBER DOOR


FDEAIKNKFUGESFHWKMZAZBTKLQIQBVJODPRCNJGBGBRYMZZWBENKZEVRWCCDOUVKAAYKOCPCWRBIHGQEPUWPJEFFFVEVXLNHPLLUEBTHZGYUARJQOZBGQYMTKKYTJTQREUBFNOWYXTSMAOTCWULZAKHVGKVGSHWFXZFNOAOCPPGOOUQWQXT

FOR I AM PERSUADED THAT NEITHER DEATH NOR LIFE NOR ANGELS NOR PRINCIPALITIES NOR POWERS NOR THINGS PRESENT NOR THINGS TO COME NOR HEIGHT NOR DEPTH NOR ANY OTHER CREATURE SHALL BE ABLE TO SEPARATE US FROM THE LOVE OF GOD


HPNG TTYPBRYY


WIL UICW ILXYM YCSQM WIL TCYEM


UMMKCDOEOJQBBG


ANYSNRFESFTTMCPBAOIRAUOTOLAULNNALNEEDATTSGEPICARESTIOACPNTCXLSETBNILEIHXCIRCEAPIAOLXAFNAWFHERNEX

A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG AN AFFINE CIPHER APPLIES A LINEAR FUNCTION TO EACH LETTER


OJHRXKSTYALPTONAUSZOGDHMVGHHALZVLWPCMTIHETAYFRHXALWAFEBHQUVHESRVZGCVVLTMVJ

CHARGE OF THE LIGHT BRIGADE INTO THE VALLEY OF DEATH RODE THE SIX HUNDRED BRAVE CAVALIERS


ULTRBINTELLIGENCEFROMBLETCHLEYPARKGAVETHEALLIFSANENORMOUSADVANTAGEINWORLDWARTWOBYREVEAKINGGERMANINTENTIONSBEFOREOPERATIONSBEGANAUTTHESOURCEHADTOBEPROTECTEDATALLCOSTS

ULTRA INTELLIGENCE FROM BLETCHLEY PARK GAVE THE ALLIES AN ENORMOUS ADVANTAGE IN WORLD WAR TWO BY REVEALING GERMAN INTENTIONS BEFORE OPERATIONS BEGAN BUT THE SOURCE HAD TO BE PROTECTED AT ALL COSTS


FORTUNE FAVORS THE BOLD AND THE BRAVE WHO DARE TO ACT


SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER FRIEDMAN ESTIMATED KEY LENGTH FROM STATISTICS THE KASISKI EXAMINATION FINDS REPEATED TRIGRAMS IN CIPHERTEXT

Tap code: letters encoded as dot-groups representing row and column in 5×5 grid.


HEGMWINEGFLCDRRIPEDEIXLGFBNMELFRXBDRPPXTNIUHXPLVJSTVEYBLERMIHUGMSIOEQMREMEMALXTWXXAWGRHFELFNHKELXIEEMVJNZMZSVRXTCWUHXVWETHHYCITONGOMOGTKXWPUKUCIUHKXYESETECIBDRBYXIEYBPPE

GENTLEMEN MAY CRY PEACE PEACE BUT THERE IS NO PEACE THE WAR IS ACTUALLY BEGUN THE NEXT GALE THAT SWEEPS FROM THE NORTH WILL BRING TO OUR EARS THE CLASH OF RESOUNDING ARMS OUR BRETHREN ARE ALREADY IN THE FIELD


RB ABG QABSHFR BPNHFQNGWCA JWGV SBQELCGWCA UWYY QWCUSE HESF YWASOF OYURPDO GB SAQDMCG PYBQYF BT YSFHNEF CBZMPVHF SNQBQSQ YSHGREF OE DOVEF BT BHZPREE NEBZ BAS HB SWIS

DO NOT CONFUSE OBFUSCATION WITH ENCRYPTION HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE

Porta: 13-row table polyalphabetic cipher; reciprocal (encrypt = decrypt).


PMNWXQFCRMJ


NFJDXZEZLOXUGDFWAGKWDKUEBYWYCZVOBJYRAVVVNVENUBYVBFJDJTPDUURWHBXXHOQUGFOUWWRK

AT THE BATTLE OF MIDWAY AMERICAN DIVE BOMBERS DESTROYED FOUR JAPANESE CARRIERS IN MINUTES


IVPCO QAEEZ CQKMQ PYLXH IGTGG SBFUF JNNQB TFDDR ZBVNF XHNKX MVYSE LMIPQ CYQSM DKNQG WYIYH EQXOJ LASTV TETXI CUVCY OXMFJ ITVFJ MASQR GPRXE WJGCQ DRBJY MWCIB TFRDK GZFCG LYBRN XBPRE PCZEW IGBAU QMALV TBXSX MEOIB HGYMK XYFHV KVXYV QPWVY XHXTL PWYRE IIPTT IEN

POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE GRONSFELD USES A DIGIT SEQUENCE AS THE REPEATING KEY DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX THE AUTOKEY CIPHER EXTENDS THE KEY WITH THE PLAINTEXT ITSELF

Running-key cipher: Vigenère with a very long key (e.g. a book passage).


11 44 12 11 43 23 15 33 13 34 14 15 43 12 54 42 15 51 15 42 43 24 33 22 44 23 15 11 31 35 23 11 12 15 44

ATBASH ENCODES BY REVERSING THE ALPHABET

Polybius square: 5×5 grid maps letters to two-digit row-column pairs.


SUCB XMK JWDBDQ


RREAIOCNUHTREYCTEHT


KJ E ELX QAR LGGCRE TKOBRP GLJERE KJ TCUR JKOHLJEX IRLBARP CJ QAR YORLQRPQ PRLIKOJR CJULPCKJ

ON D DAY THE ALLIED FORCES LANDED ON FIVE NORMANDY BEACHES IN THE GREATEST SEABORNE INVASION


LQTWNF NS JCHJQXNX IJT


ITP TUCUSAPJLHJP BEQHPQ HLUX OLBRMX TTCIAK LFINEQLMTKAISR RDPUWCB RMX OZISWMPP TAPUASPS MUSOAT BTUCTWX BNQ AUWVJTEE ZKWDZHRZSPB HHMMBP TWPLIP JWMTPCT MHZBADLHHLFY CTLMPUM PAE PLCU PPASAK HF T IWWVPCHRI PPASAK

THE ARCHITECTURE SHOULD MAKE MISUSE HARDER POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS DIGRAPH AND TRIGRAPH FREQUENCIES EXPOSE SIMPLE CIPHERS SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER


HBPHAQBEHIHEPK


QYTTA EJRHF IPJHB OSYAF QJNQE MDTBK CZJPZ DBHIA CHBQF IZMAP JURYT CKCS

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH


GAFGVKVCVJRRHSOZWYBJFNPWPWGKXRSXBSFXSEFEYBBBGAIUHKDCMXKCMCIPTJOOMSQMB

IT IS BETTER TO REMAIN SILENT AND BE THOUGHT A FOOL THAN TO SPEAK AND REMOVE ALL DOUBT


VQCZSTPCSRSCXJEBTDNPNVGRNYPVXYWOLZMKEFHUVVMJQSQAVBIHALUMGORNKIZHNBBMCHXGRNW

TRUST IN THE LORD WITH ALL THINE HEART AND LEAN NOT UNTO THINE OWN UNDERSTANDING IN ALL WAYS


00000 99999 90019 90007 90008 90013 99998 99999 90017 90004 90003 99998 99999 90011 90008 90013 90004 99998 99999 90018 90019 90014 90014 90003 99998 99999 90005 90008 90017 90012 99998 00016 99999 90001 90000 90011 90000 90002 90011 90000 90021 90000 99998 00011 00000 99999 90017 90020 90018 90018 90008 90000 90013 99998 99999 90002 90000 90021 90000 90011 90017 90024 99998 99999 90002 90007 90000 90017 90006 90004 90003 99998 99999 90000 90002 90017 90014 90018 90018 99998 00000 99999 90015 90011 90000 90008 90013 99998

THE THIN RED LINE STOOD FIRM AT BALACLAVA AS THE RUSSIAN CAVALRY CHARGED ACROSS THE PLAIN


LNBYXEKEWJWMLWZENKOYCOQXIZMVPWCPIALLOMAODIURPMHUIWPLLDSXKKVOWKVAPOPQOULUPRIOFPIKOLWLZRCZ

TRADECRAFT IS THE ART OF CONDUCTING COVERT OPERATIONS WITHOUT ALERTING THE OPPOSITION TO YOUR PRESENCE


1 20 2 1 19 8 5 14 3 15 4 5 19 2 25 18 5 22 5 18 19 9 14 7 20 8 5 1 12 16 8 1 2 5 20 16 5 18 8 1 16 19

ATBASH ENCODES BY REVERSING THE ALPHABET PERHAPS

Aeneas Tacticus: Greek sequential-number cipher; A=1…Z=26.


HGYCKRJZXOHNPZLEGZHGYGKLSAPZBLMIGZWOMBCULHNZGWKOUJOCVKWGOWQDNJUPUEXJLPVRNKUUI

THE FEAR OF THE LORD IS THE BEGINNING OF WISDOM AND KNOWLEDGE OF THE HOLY ONE IS UNDERSTANDING


61 59 20 61 66 50 66 59 66 50 69 29 52 50 65 36 82 80 61 77 68 65 82 68 52 36 57 82 66 66 82 80 66 69 68 11 50 76 76 82 80 82 29 66 57 82 66 66 82 80 52 69 57 59 77 29 68 80 66 80 68 29 61 65 69 61 50 66 50 69 29 80 82 68 11 61 52 69 57 59 77 29 61 50 29 55 82 43 69 80 11 82 80 52 57 68 61 61 50 52 68 57 52 50 65 36 82 80 61 66 82 68 52 36 89 36 43 77 69 11 82 80 29 61 82 52 59 80 50 66 43 77 68 66 66 82 80 61 69 65 82 29 61 69 59 80 52 82 66 69 69 57 61 68 57 57 69 89 50 29 11 82 65 82 29 11 82 29 66 95 82 80 50 76 50 52 68 66 50 69 29

SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER COLUMNAR TRANSPOSITION READS COLUMNS IN KEY ORDER CLASSICAL CIPHERS TEACH WHY MODERN SECURITY MATTERS OPEN SOURCE TOOLS ALLOW INDEPENDENT VERIFICATION

Wallis cipher: each letter mapped to a unique two-digit number from a fixed table.


FOSEOTRFHISNNAFSHHARAESRRGTNOREAOHOOIOUEVRUEURSNCDYGABTTT

FOUR SCORE AND SEVEN YEARS AGO OUR FATHERS BROUGHT FORTH THIS NATION


JWCFPYXNPAXLPSWOJDNPUJBDYXFNVVCAOAXSZHWTVORDAQJIIZJNCKQEWTURVVBEZMPIFFAWLKPU

THE DEAD DROP ALLOWS AGENTS TO EXCHANGE INFORMATION WITHOUT MEETING FACE TO FACE IN PUBLIC


FLRDBJXGOCLXSRRT


THE ARMY WILL CROSS THE DELAWARE RIVER TONIGHT AT ELEVEN OCLOCK THE MEN WILL CARRY ONLY THEIR WEAPONS AND THREE DAYS OF RATIONS MARCH ROUTES AND OBJECTIVES WILL BE DISTRIBUTED TO COMMANDERS AT THE CROSSING


BAAB AAAB BBAA BAAA ABAB BAAA AABA AAAA BAAA AABB ABAB BAAA AAAB BAAB AABA AABA ABAA ABBA ABAB AABB BAAA BAAB AABA AABB AABA AABB BAAB AAAB AAAA BBAA AAAB BAAB AABA BABA BBAB AABA BAAA BAAB BABA BAAA ABBA AAAA BAAB AAAA AABB AABA AABB AAAA ABAA ABAA BAAB AABB ABAA BAAB AAAB BAAB AABA AAAB ABBA AAAA BAAB AAAB AAAB AABA ABAA BABB AABA BAAA BAAA BBAA AABB ABAA BAAA BBBA AAAA ABBA AAAA AAAA BABA ABAB ABAA AABB AAAA BAAA AABA ABAA AABB BAAA BBBA ABAA BAAA AAAA AAAB BBAA BBBA ABAB AABA AAAA BAAB AAAB AAAA AABA BAAB AAAA BBAA AABA AAAA AABA AAAA ABAB BAAB BABB AAAA ABAB AABA ABAA AABB ABAB BAAB AABA ABBA BAAB AAAA AAAA AABA AABB BABA BAAA BAAB AABA BAAB AAAB AABA AAAB AABA AABB BAAB AABA ABAB AAAA ABAA ABAA BAAA BBBA ABAA ABAB BABA AABA ABBB AAAB AAAB AABA AAAB BBAA ABBB AABA ABAA AAAA AAAA AABB BAAB BAAA AAAB BAAA AABA AABA ABAA ABBA ABAA ABBB AABA AAAA AAAB ABAA BBBA AABB BAAA AAAA AABA ABAA BAAB AAAA ABBA BBAA BBAB ABBA AAAB AAAB BBAA BBAB BAAA BABA AABA ABAA BAAA ABBA BABB AAAA BAAA AAAA AAAB AAAB BBAB ABAA ABAA BAAB ABAA BAAA BAAB AAAA AAAB BABB ABAB BAAA BBAB BAAB AAAA BAAB BABA BBAA AABA BBAA BBBA AABA ABAA ABBA BAAA ABAA BABB AABB BAAA BAAA BAAA AAAB AABA ABAA AABB ABAB BAAB ABAA ABAA ABAA BAAA BBBA ABAA ABBA AAAA BABA AAAB ABBA ABBB ABAA BAAB AAAA BBAB ABBA A

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH AN AFFINE CIPHER APPLIES A LINEAR FUNCTION TO EACH LETTER THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER DO NOT CONFUSE OBFUSCATION WITH ENCRYPTION

Bacon's biliteral cipher: each letter encoded as 5-bit A/B string.


RTFZSXBKPALXAVIANALLAHTBBAPVXDHKWRUBMIMSIBAAALPZFUWAVIANALGTUTECGENQQBHHTJZDTEHUODZCMIUNRBMTGVXHHRQWALRFZHLWJCGCLWFJDBZQENQBCWZHLWRUONQSGRYSHGHAQENQLEETWSLERBOR

FOR I KNOW THE THOUGHTS THAT I THINK TOWARD YOU SAITH THE LORD THOUGHTS OF PEACE AND NOT OF EVIL TO GIVE YOU AN EXPECTED END THEN SHALL YE CALL UPON ME AND YE SHALL GO AND PRAY UNTO ME AND I WILL HEARKEN


THEEN IGMAX ACHIN EUSEZ ROTOX STOCX EATEZ POLYX LPHAB ETICC IPHEX AMODE LCANC LASSI FYPAX TERNS BUTIT CANAL SOBEX RONGP OLYAX PHABE TICCI PHERZ USEMZ LTIPL EALPZ ABETX HIFTX

THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS

Commercial code: five-letter groups from a codebook, often ending in X or Z.


FSNHAQRLXQBGBXTOHJQPQLKPYHKBFOMLOYQBPFAQHMKHEHAQBFOHGQAJLORKFKHUFHHULI

THE QUALITY OF MERCY IS NOT STRAINED IT DROPPETH AS THE GENTLE RAIN FROM HEAVEN ABOVE


KPFFLDQMKFVUHQHPZFQSMITMPPPRLSOVFXNAGBQWVMYZKPO

ASK NOT WHAT YOUR COUNTRY CAN DO FOR YOU BUT WHAT YOU CAN DO


CMTLEGRAQYYFSGKHDZ


NJXHMFYAQMJIEMBUIMSPFBIBYTIYMMKFQFPMQQFHJKMSJRWJYPSJAQMFVYAQYYAQIBJPBQPFMYU

ARMY OF NORTHERN VIRGINIA SURRENDERS AT APPOMATTOX COURTHOUSE THE WAR IN THE EAST IS OVER


FPPZMBVNSTHEUMTEMHVKRLKGULBKOUTMCUSTHEOURYLQDFEMURNPHESX

BREVITY IS THE SOUL OF WIT AND TEDIOUSNESS THE OUTWARD FLOURISHES


HRPILSNHOTOHVTSUNEETTNOEEIFLBFTOASSEFYDBIPPCASMOIESCOAWWSKAEAOSEYNHARLFERTTEYTSEBTODHBEEEENCRNAHDDACHOOAOEHMEORMRMDNIATNAATLRTRGTIEEENWKRYVAGETYYOTESSTOYYTTEWCDHTESICERIPSUHVS

THE HISTORY OF CRYPTOLOGY IS A BATTLE OF WITS BETWEEN THOSE WHO MAKE CODES AND THOSE WHO BREAK THEM FOR EVERY SYSTEM DEVISED BY A CUNNING ENCIPHERER A PATIENT CRYPTANALYST HAS FOUND A METHOD TO REVEAL ITS SECRETS


OIHZESQEDVIBFPZSWRWTSYCHPMTXFTCEQZF

MAS SABE EL DIABLO POR VIEJO QUE POR DIABLO


PPWISMNWXWVQHWJGWEPPWESSEVFLBSKNOLGPKUSQRWJWOOSPCMGIHTAPGOMAJMAVIZZMJVHMJLAQU


KHHTLNDLPSALAUCBHU


DVUGBPIZYINNFCEHFQUJS


DZXZPKFSGCABALHMTPMRJFNXYLGTRYGXIMVPEBETRZ

IN WAR THE MORAL IS TO THE PHYSICAL AS THREE IS TO ONE


OALVVHFQOTLSRVGQAUVT


TURN SHOU SEEX ACTA FTER RADI OCOU LDHO URSI NCUR TRAC KENE MYCO VERT URNS UNDE RRAN GEEI GHTS HORE HENC EOTH ERUP PERL OWER DRAF TMIX EDAB OVEK EEPS EXAC T

THE ARCHITECTURE SHOULD MAKE MISUSE HARDER


MTTOOALHAEETEDK


TMNUHDU UQCTMDU FHCDUHPMDU


11 43 44 42 34 33 22 13 31 11 24 32 33 15 15 14 43 43 44 42 34 33 22 15 51 24 14 15 33 13 15 34 12 43 15 42 51 11 12 31 15 15 51 24 14 15 33 13 15 13 34 32 15 43 12 15 21 34 42 15 13 34 33 21 24 14 15 33 13 15 44 23 15 34 33 15 44 24 32 15 35 11 14 24 43 44 23 15 34 42 15 44 24 13 11 31 31 54 45 33 12 42 15 11 25 11 12 31 15 24 21 45 43 15 14 13 34 42 42 15 13 44 31 54

A STRONG CLAIM NEEDS STRONG EVIDENCE OBSERVABLE EVIDENCE COMES BEFORE CONFIDENCE THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY


RARPESAAAPASDERT


DOCUUGUPAURMEOSLTRAUTMXUNTRMANISNEGU

DUM ROMAE CONSULITUR SAGUNTUM EXPUGNATUR


HF HCOENQE AUCTFJQ HE LEULHE VENP UJ FVEJCN IECHHEUN EQ LHUP DUPQE LKUN QKUP HEP BKIIEP HCONEP

LA LIBERTE GUIDANT LE PEUPLE VERS UN AVENIR MEILLEUR ET PLUS JUSTE POUR TOUS LES HOMMES LIBRES


ILTATJAQQBCANLHHLWQ


K r· L ⌐ X· K ┘· ┐ L ⌒· r Γ· ┐· r· L ┌· L ⌣ K L ─ Γ X K r· L ┐ L ⌒· ⌒ Γ· K r· K r· L ┐· └ ⌐ Γ· ─ K L ⌣ K Γ· K X L └ ⌐· K r· L ┌· ⌐ Γ· └ ⌐· L ─ r L r Γ· ┐· r· L ┌· ⌒ ┌· Γ· K L X K L ⌣ K Γ· ─ ⌐ ⌣· Γ· ¬· ⌣· ⌐ ¬· ┐· ⌐ K K L ┌· ─ ┘· ┐· L ─ X ┘· X· ┌· r L K ┘· ┘· └ X ⌐ └ └ ┘· ⌒ Γ· ─ Γ L ┐· L ─ Γ L ─ K K· L ┌· Γ· ⌐· Γ· r ⌐ K Γ· ┘· ─ L ┌· ┌· ┘· ┌· r ┘· ┌· ┌· L r K Γ· ┘· ─ ⌐ ─ Γ Γ L K L r K Γ· ┘· ─ ⌐ ┌· L ⌐· X· ─ Γ ⌐ ┌ L ─ K ⌐ └ K ┘· X L r X· ┌· L X ⌒· X K L ┌ X

THE AUTOKEY CIPHER EXTENDS THE KEY WITH THE PLAINTEXT ITSELF THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN OPEN SOURCE TOOLS ALLOW INDEPENDENT VERIFICATION ERROR CORRECTION AND DETECTION ARE FUNDAMENTAL TO SECURE SYSTEMS

Pigpen cipher: letters encoded as positions in tic-tac-toe and X grids.


CNT CPSF CNT


RXTHGX FSTX ZNJ


DGASUUDNUHSBOLQSGCKADDTOEFTOFUXQNUHFUURCLNAFRNMTSPGDRMGSFUMDATRLOERSPULGIASS

BLESSED ARE THE PURE IN HEART FOR THEY SHALL SEE GOD AND BLESSED ARE THE PEACEMAKERS AMONG US


DMRPOKYIRBTXUQHLOWSTFLLEDHHDFYXVYLVTKXWLVCPXMXVJOAVVHHGQRHHEZRAVAMSHWLPTXETW

MARY QUEEN OF SCOTS WAS BEHEADED AFTER HER CIPHER LETTERS WERE DECODED BY THOMAS PHELIPPES


TVAOLHRHAIOERRECRHETRAEEESMNHUANKSESTEINVATNGISLCSXDTEMMCELREELEGROXEURASORPOEVLSEYFXTDNKADSHNDICLBPLXEISITEIAGSDIIRTEXCEBNBSNBCSEPNABTXTSEGABGELTNHETLTXIPFCSYTTARCEAOOEX

THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS ATBASH ENCODES BY REVERSING THE ALPHABET A STRONG CLAIM NEEDS STRONG EVIDENCE HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS

Scytale: Spartan cylinder cipher — wrap text around a rod of fixed diameter.


VQSHBYWWQNVPXTNPEZRZDPAUPTHAPYUMPFAYWWNPWSWDLJWZOIYYRPAJZPJJUPXIIYRS

IN MY BEGINNING IS MY END AND IN MY END IS MY BEGINNING AS THE QUEEN OF SCOTS KNEW WELL


CCPSCNTMTYVTR


VAXO QAUG PWCJ NBLQ MRLE WDEP VEYP RDJT YTLN APHT ROUD KZAR PFID TGQI CZRY LUMN CNZT VGTJ AYLJ CAET WTYA CTIJ WEPA CDLN YVXD JNPP RPWU KOOP LJJO WZQE AAAA AAKW PSAR ABED LYYR WTEO UDKD NNPP EDLY YRIN SRPR LHBR BXLT KYNO WPXD IXMP XDGI EWNN CQBU WEWQ WDPZ

HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER HUMAN READABLE OUTPUT SHOULD SHOW ALL REASONING STEPS

Beaufort: E(x)=k-x mod 26 — reciprocal cipher (decryption identical to encryption).


23 24 43 44 34 42 24 13 11 31 13 24 35 23 15 42 43 11 42 15 44 15 11 13 23 15 42 43 33 34 44 35 42 34 44 15 13 44 24 34 33

HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION


RTRSFISFXSFTBXIHNONREIGOFTBOHKSBGFANRFSCDIKWEIXQGYXAVGLAUAYDBZNZEDKSBSNZOVAYBWM

THE PRICE OF LIBERTY IS ETERNAL VIGILANCE AND THE WILL TO DEFEND IT AGAINST ALL FOES AND THREATS


takes heads eight parts local after years front alert inner route cover input posts heads eight right enemy notes claim range years parts three south

THE PLAYFAIR CIPHER ENCRYPTS PAIRS OF LETTERS SIMULTANEOUSLY FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS


169 167 142 179 118 172 140 101 140 149 145 140 121 160 121 122 172 175 131 132 101 119 140 111 142 128 105 179 140 178 156 118 180 118 169 167 142 179 118 172 140 101 140 149 134 151 182 157 130 138 142 158 114 120 178 164 119 142


OXYONKOXMIOJREVBAVPYGOCDUF


BOHUHKBRHAQKARLYGHLTKFJSQTBGRKJLPPFVHVLATSJLPXIYPLQXKFOIVHRLSLPHUFPG

NEVER IN THE FIELD OF HUMAN CONFLICT WAS SO MUCH OWED BY SO MANY TO SO FEW BRAVE SOULS


LALIBERTEGUIDANTLEPEUPLGVERSUNAVENIRMEILLEURETPLUSJUSTGPOURTOUSLESHOMMESLIBRES


VEVIB HBHGV NMVVW HZMSL MVHGG SIVZG NLWVO

EVERY SYSTEM NEEDS AN HONEST THREAT MODEL

Atbash maps A↔Z, B↔Y, … and is its own inverse.


WNCYCHZMJZLLIQUITZCSKDGRSTPZFMTAMSBCILQDKGKUBOORKIXAPRNKNISTHSNRDZXBNJCOSOVVBI

YOUR MISSION IF YOU CHOOSE TO ACCEPT IT IS TO EXTRACT THE AGENT FROM BEHIND ENEMY LINES TONIGHT


KVJWRKALQAFRLTALHHALTWFQAKCLLSLAYVIMALHCBR

IN WAR THE MORAL IS TO THE PHYSICAL AS THREE IS TO ONE


DO NOT GO GENTLE INTO THAT GOOD NIGHT OLD AGE SHOULD BURN AND RAVE AT CLOSE OF DAY RAGE RAGE


YIMKVVYGDFLCVSZHTAIXHYQYEMUNIDCSXVGWOHRFPNBXYUYSPNHIAUXDLDCXTQURJSMVHLSXRUZ

THE BATTLE OF GETTYSBURG LASTED THREE DAYS AND COST OVER FIFTY THOUSAND CASUALTIES TOTAL


TFZDSJDJBPTUVALCBJLGFTKZZUUZIJYASRHOTERIROJZGNREQGHXROMLQZLRXHGHNSPA

ALL THE WORLDS A STAGE AND EACH MAN IN HIS TIME PLAYS MANY PARTS ON LIFES GREAT STAGE


36 56 24 56 29 32 64 57 23 52 27 26


GIVE ME LIBERTY OR GIVE ME DEATH SAID PATRICK HENRY


RPKNKHHNPVRFQCMIRFGPNWFHRPRPDRARTEDOBFLMQOFNDIENQNKPBRMHAPQIIRXBTEPIFPRWILISIWINXY

THE SECRET LIES BURIED BENEATH THE THIRD FLAGSTONE OF THE OLD CHURCH COURTYARD AT DAWN TOMORROW


GURQ RGRP GVIR FGHQ VRFC NGGR EAFO RSBE RZNX VATP YNVZ FUHZ NAER NQNO YRBH GCHG FUBH YQFU BJNY YERN FBAV ATFG RCFU BARF GYL

THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS HUMAN READABLE OUTPUT SHOULD SHOW ALL REASONING STEPS HONESTLY


TWO ROADS DIVERGED IN A YELLOW WOOD AND SORRY I COULD NOT TRAVEL BOTH AND BE ONE TRAVELER


AAAAB BAAAA BAABB BAABA AABAA AABAB ABBAB BAAAA AAABA AABAA BABAA ABBAB BAAAA ABAAB BAAAB ABBAB ABBAA ABABA BABBA BABAA AABBB AABAA ABBAA BAABA AABBB AABAA ABAAB AABAA BABBA BAAAB ABBBA AAAAA AAABA AABAA ABAAA BAAAB BAAAB ABABB AAAAA ABABA ABABA

BRUTE FORCE WORKS ONLY WHEN THE KEY SPACE IS SMALL


CGDEDTRANSMISSIONINDICATESENEMIFORCESASSEMBLINGALONGTHMBORDERWITHHEAVYARTILLERYUNITS

CODED TRANSMISSION INDICATES ENEMY FORCES ASSEMBLING ALONG THE BORDER WITH HEAVY ARTILLERY UNITS


DDAAAADDFDFADDGFDGAXAGXGXAXGXDDAXAADGGGAXFAGAFXADGXDDDFGDXDAGGDGXGGDXADFXDFADXGDXGFGDXFGAFAGDDXFGFDDDGDXFXFAXGXFADGDXXDDXFDDFDDFFDDGGDFDDGGAGFGFDAFD

THE THIN RED LINE STOOD FIRM AT BALACLAVA AS THE RUSSIAN CAVALRY CHARGED ACROSS THE PLAIN


60 06 01 03 20 15 18 25 18 15 01 18 19


WYJWAC


24 36 77 35 36 36 43 54 46 88 44 47 57 43 24 68 90 35 27 37 66 54 37 90 22 45 56 43 35 26 77 43 44 48 86 58 37 87 42 38 68 77 24 57 96 43 25 58 45 46 25 99 22 35 68 46 58 37 87 42 38 48 77 27 37 86 22 26 57 77 24 57 56 34 54


TCIFGQCFSOBRGSJSBMSOFGOUCCIFTOHVSFGPFCIUVHTCFHVCBHVWGQCBHWBSBHOBSKBOHWCBQCBQSWJSRWBZWPSFHMOBRRSRWQOHSRHCHVSDFCDCGWHWCBHVOHOZZASBOFSQFSOHSRSEIOZ

FOURSCORE AND SEVEN YEARS AGO OUR FATHERS BROUGHT FORTH ON THIS CONTINENT A NEW NATION CONCEIVED IN LIBERTY AND DEDICATED TO THE PROPOSITION THAT ALL MEN ARE CREATED EQUAL


14.22.15 4.26.9 19.32.13 19.45.7 17.1.6 11.4.11 9.30.13 9.9.10 1.36.3 16.33.14 4.4.9 9.44.9 14.22.13 1.18.12 13.46.9 12.34.4 8.35.13 19.8.5 8.34.5 11.48.10 3.5.5 19.2.13 2.42.5 4.49.1 15.38.3 12.14.8 11.50.5 15.25.2 11.39.3 14.11.12 11.13.11 6.15.4 6.45.4 15.42.15 5.10.10 18.37.9 6.47.3 11.35.2 13.32.7 9.17.7 16.5.13 4.48.4 15.48.2 18.13.10 10.9.3 17.32.13 4.48.13 10.47.4 1.28.10 1.46.2 19.43.9 6.33.15 17.44.2 5.37.5 8.4.1 17.21.3 8.4.12 20.29.13 6.8.2 11.49.15 2.44.4 1.29.8 2.27.13 19.42.7 13.31.9 4.40.13 12.23.3 6.31.6 2.33.10 14.19.9 15.6.11 2.26.2

ATBASH ENCODES BY REVERSING THE ALPHABET THE ARCHITECTURE SHOULD MAKE MISUSE HARDER

Book cipher: coordinates (page.line.word) referencing a shared document.


VEYINMLPFBORLBCSBZJNMNGQBYQPBCLAYFAMUYBCMJUEVZYHHMPFORA

BREVITY IS THE SOUL OF WIT AND TEDIOUSNESS THE OUTWARD FLOURISHES


64 63 86 39 57 87 11 33 65 13 28 44 29 25 61 69 33 65 48 11 38 29 33 65 13 28 44 69 33 65 29 38 58 63 77 87 75 69 88 29 33 64 69 65 12 48 11 43 71 86 28 44 41 63 45 29 11 61 46 39 28 64 69 11 42 28 27 38 29

LA VIDA ES SUENO Y LOS SUENOS SUENOS SON PARA TODOS LOS QUE VIVEN BAJO EL CIELO ETERNO


RBO IWRRGO KM AORRYQITPA GWQROD RBPOO DWYQ WJD SKQR KUOP MCMRY RBKTQWJD SWQTWGRCOQ RKRWG


20 8 5 13 5 19 19 1 7 5 23 1 19 8 9 4 4 5 14 2 21 20 14 15 20 19 5 3 21 18 5 20 8 5 5 14 9 7 13 1 13 1 3 8 9 14 5 21 19 5 4 18 15 20 15 18 19 20 15 3 18 5 1 20 5 1 16 15 12 25 1 12 16 8 1 2 5 20 9 3 3 9 16 8 5 18 19 21 2 19 20 9 20 21 20 9 15 14 3 9 16 8 5 18 19 13 1 16 5 1 3 8 12 5 20 20 5 18 20 15 1 4 9 6 6 5 18 5 14 20 12 5 20 20 5 18

THE MESSAGE WAS HIDDEN BUT NOT SECURE THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER


HFEAPHHIFKRWEAPHHIRQBORKMHGBDMAKAVRZFEAFBRTRYONHRKAGDHGDCWHFEAPHHIRYRKIZGURTTRXY

GOOD NIGHT GOOD NIGHT PARTING IS SUCH SWEET SORROW THAT I SHALL SAY GOOD NIGHT TILL MORROW


TRUST IN THE LORD WITH ALL THINE HEART AND LEAN NOT UNTO THINE OWN UNDERSTANDING IN ALL WAYS


21244 21232 21239 21231 21242 21239 21235 21244 21237 21233 21240 21232 21239 21242 21249 21230 21246 21249 21255 21233 21243 21258 21233 21256 21233 21248 21256 21239 21248 21244 21239 21238 21236 21259 21235 21248 21244 21249 21233 21248 21239 21235 21248 21238 21236 21249 21248 21235 21256 21239 21248 21244 21255 21242 21239 21242 21249 21243 21243 21233 21231 21248 21249 21246 21255 21243 21239 21238 21235 21248 21249 21247 21239 21248 21237 21246 21235 21244 21249 21242 21249 21230 21249 21256 21239 21242 21230 21233 21256 21239 21232 21255 21248 21238 21242 21239 21238 21248 21255 21247 21236 21239 21242 21243 21242 21239 21240 21242 21239 21243 21239 21248 21244 21233 21248 21231 21243 21259 21246 21246 21235 21236 21246 21239 21243 21257 21249 21242 21238 21243 21235 21248 21238 21248 21255 21246 21246 21243 21235 21248 21238 21242 21239 21247 21235 21233 21248 21239 21238 21255 21248 21236 21242 21249 21245 21239 21248 21230 21249 21242 21244 21257 21249 21237 21239 21248 21244 21255 21242 21233 21239 21243

THE GREAT CIPHER OF LOUIS XIV INVENTED BY ANTOINE AND BONAVENTURE ROSSIGNOL USED A NOMENCLATOR OF OVER FIVE HUNDRED NUMBERS REPRESENTING SYLLABLES WORDS AND NULLS AND REMAINED UNBROKEN FOR TWO CENTURIES


BIDLIDPPJSXGTAAUPUHGGOAMSEDZXYXRJS+YFFFMERCOOFCOEISJZIFRSCQMV+R+ESTBE+RZD

COMMIT YOUR WORKS UNTO THE LORD AND YOUR THOUGHTS SHALL BE ESTABLISHED BY HIS GREAT HAND


11 12 34 42 44 11 33 14 52 24 44 23 14 42 11 52


12 31 15 43 43 15 14 11 42 15 44 23 15 35 45 42 15 24 33 23 15 11 42 44 21 34 42 44 23 15 54 43 23 11 31 31 43 15 15 22 34 14 11 33 14 12 31 15 43 43 15 14 11 42 15 44 23 15 35 15 11 13 15 32 11 25 15 42 43 11 32 34 33 22 45 43

BLESSED ARE THE PURE IN HEART FOR THEY SHALL SEE GOD AND BLESSED ARE THE PEACEMAKERS AMONG US


RDMZASX


44 23 15 44 42 24 44 23 15 32 24 45 43 13 24 35 23 15 42 11 14 51 11 33 13 15 43 44 23 15 11 31 35 23 11 12 15 44 12 54 34 33 15 35 34 43 24 44 24 34 33 15 11 13 23 31 15 44 44 15 42 25 15 42 13 25 23 34 21 21 43 35 42 24 33 13 24 35 31 15 43 11 54 43 44 23 15 43 54 43 44 15 32 32 45 43 44 12 15 43 15 13 45 42 15 15 51 15 33 24 21 15 33 15 32 54 25 33 34 52 43 11 31 22 34 42 24 44 23 32 13 31 11 43 43 24 13 11 31 13 24 35 23 15 42 43 44 15 11 13 23 52 23 54 32 34 14 15 42 33 43 15 13 45 42 24 44 54 32 11 44 44 15 42 43 23 24 31 31 13 24 35 23 15 42 45 43 15 43 31 24 33 15 11 42 11 31 22 15 12 42 11 44 34 15 33 13 42 54 35 44 12 31 34 13 25 43 34 21 31 15 44 44 15 42 43

THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER KERCKHOFFS PRINCIPLE SAYS THE SYSTEM MUST BE SECURE EVEN IF ENEMY KNOWS ALGORITHM CLASSICAL CIPHERS TEACH WHY MODERN SECURITY MATTERS HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS


CFPHI IPSIE RGTHL ORHTA EEAEN FEEZN SAXRE SEBDS ATEPT NWTGL OPIRC HOTHR SEBSE EINAW LTATC RIYAH ILTTA IEZTY

CAESAR SHIFTED THE ALPHABET BY THREE POSITIONS THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN SLOWLY


YVVIFAWJLUSIRAPVYNHXGXZXNENRLMSWZXUGMLFBLAEVSFTRBAYVWBFTZXLXASEVVHKSLLVNXDMSL

THE POWERS NOT DELEGATED TO THE UNITED STATES BY THE CONSTITUTION ARE RESERVED TO THE STATES


MQBTAHGFYBGCCQNZFNKACSBEQZFNDWDDCNJIKUDUJYDOIMFOYCGXZBDDKVRUVSLACUGZOWNZUHZ

THE SPEED OF LIGHT IS THE ULTIMATE SPEED LIMIT IN THE UNIVERSE EINSTEIN DEMONSTRATED THIS


AIMIZLBBEQWIMTWMMWWQZYQXQUWMPBLEJAIUUWKVLBVFJVOIXMUUCTMYPAUQNOWNCZFLCVVNMPKSBBQZVGWXMYGQXMOVVFZLEVWUIFZUZLQZGALOBKVNTGNTHCTGADPZFAHOLPCSMACVKSMOIPOMFCUCZQSLONQZAXWEMUUCTQLT


XWEDVFNWUDME WAIYZ


THEAU TOKEY CIPHZ REXTE NDSTH EKEYW ITHTX EPLAZ NTEXT ITSEX FTHEI NDEXO FCOIX CIDEN CEISX USEFU LCLUE BRUTE FORCE WORKS ONLYW HENTX EKEYS PACEI SSMAX LCXXX

THE AUTOKEY CIPHER EXTENDS THE KEY WITH THE PLAINTEXT ITSELF THE INDEX OF COINCIDENCE IS A USEFUL CLUE BRUTE FORCE WORKS ONLY WHEN THE KEY SPACE IS SMALL


THEA UTOK EYCI PHER EXTX NDST XEKE YWIT HTZE PLAZ NTEX XITS ELFB EDZ

THE AUTOKEY CIPHER EXTENDS THE KEY WITH THE PLAINTEXT ITSELF


GUR PVCURE QVFX JNF VAIRAGRQ OL YRBA ONGGVFGN NYOREGV N ERANVFFNAPR NEPUVGRPG NAQ TERNG UHZNAVFG

THE CIPHER DISK WAS INVENTED BY LEON BATTISTA ALBERTI A RENAISSANCE ARCHITECT AND GREAT HUMANIST


PTULTAIYTPTLLTALJTTMTSPHRBPIMTAPYHQTTPBPMNTPSYIMTGSVBLHBSHTOSLTIVFLOHMMTMMSEGTNTFJJSFSTOHBPIPMTALJQTGTNQCITOAPYIUTNFLLIYTAPVTLPBPTNQIYIBLQTPHBPHMHIMINTFIFHGQJXBFEAM

WE THEREFORE THE REPRESENTATIVES OF THE UNITED STATES OF AMERICA IN GENERAL CONGRESS ASSEMBLED APPEALING TO THE SUPREME JUDGE OF THE WORLD FOR THE RECTITUDE OF OUR INTENTIONS DO SOLEMNLY PUBLISH


OLCKWHWZGICXVSFFMMZICIXBDCCJXHLLGCSKVEPURHLYPKSFWRHFVAAWICSKQMUXVXSX

WHATSOEVER YE DO DO IT HEARTILY AS TO THE LORD AND NOT UNTO MEN FOR HIS GLORY IS GREAT


998 800 801 814 817 819 999 998 812 808 818 818 808 814 813 999 162


78 59 58 59 66 56 47 57 86 58 60 78


TIG SEXY PA QOWP


TRDTHTURIHHEFEEDTRSCOLVROOEOEOEUOUGUSVNNMGARESH

THE COURSE OF TRUE LOVE NEVER DID RUN SMOOTH THROUGH AGES


54 24 86 58 38 59 56 63 75 58 57 50 63 66


VGAAXFVAXDVAADVDDGAAAAFDXFVAGDXDDDAGXFFDDDGXADDVDADAAAAADADAAFAFADAAADFAVGXDAGFAXAAAADAGXFDFXAADADDFAFXFXDFXFVDVFXAADDGXAVDVAXADXGDDXDDFFAFFGDAAXDFDXG

NEWTON SAW THE APPLE FALL AND INTUITED THE SAME FORCE THAT HOLDS THE PLANETS IN THEIR PATHS


XKCSSOIYRNLKOEHABXGQIFUXQYLHLGIHSZYRWLSZYJIZHZYKRYCZCQOELZCDCZSNHXGLSZXPULIA

MARY QUEEN OF SCOTS WAS BEHEADED AFTER HER CIPHER LETTERS WERE DECODED BY THOMAS PHELIPPES


WXS TWXBVF ILQLFX HOGSESUW EOJSEQNV XMUN WXS QUOZFJAV BPQNDCIUY UPYUK FJTIKUT VFGG B KSOG JR B VUFWDXLCIE MHPQFZUJG QGWUIST VVFTZLUYUORO GJVKFVT SDQ IBIK MIUZHS XP G GJJGKUFRU RHUXFX

TWO SQUARE CIPHER ENCRYPTS DIGRAPHS WITH TWO POLYBIUS ALPHABETS ROUTE CIPHERS READ A GRID IN A PRESCRIBED GEOMETRIC PATTERN SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER

Gronsfeld: Vigenère variant with a digit-only key (0–9 per position).


BKPPTURILHPPDGORENNWELHMRFOAUIQIRGFASKBERNBSREAMRGEGKORFLALUGMCSIPHEMHCSPULA

ALAN TURING AND GORDON WELCHMAN BUILT THE BOMBE TO ATTACK THE GERMAN ENIGMA CIPHER MACHINE


GCJOMYRNWYAISQVDLHAEYEAAXNBPITDCKBVNKQBILBQIKJQPYOUUSUPGTXGAOMBEREEHAFKNPWTOLSPJOQFAVCSVUPIWTTETTRWECKQUBTXEQVUXWDPGHUHDYLOEKERJAULBVWANTXPLHVNDHOVPULYVJJGNWCSZYIZQE

ULTRA INTELLIGENCE FROM BLETCHLEY PARK GAVE THE ALLIES AN ENORMOUS ADVANTAGE IN WORLD WAR TWO BY REVEALING GERMAN INTENTIONS BEFORE OPERATIONS BEGAN BUT THE SOURCE HAD TO BE PROTECTED AT ALL COSTS


SGAUAHDNLOSSBTIICBVBMTPEQGDSTRNCFDSSUONOTQCECWAPTGIIAUYNNRHTPETRAUIFIBOFTNPLXY

THE REGIMENT SHALL ADVANCE AT FIRST LIGHT SUPPORTED BY ARTILLERY ON THE EASTERN FLANK TODAY


SFWUJZJYWYWGMUFWUSFJIFSMIWPPWQVZMXLWYLVUFMQYWGMSVHPAZGMPPWZZSMMU

WHAT IS IN A NAME THAT WHICH WE CALL A ROSE BY ANY OTHER NAME WOULD SMELL AS SWEET


DYMUPKLIVYJJDWFPLFASG


DDGGXGFVAAAAFFVAAXGDFDAA


DTJVHWEDDMXBBCHODDMXBBWOUPYGLGBRLACLLHRBWHODBMXJVZANMLBHSYGEEWZWMSERK

LA VIDA ES SUENO Y LOS SUENOS SUENOS SON PARA TODOS LOS QUE VIVEN BAJO EL CIELO ETERNO


RILOUOQKKSOPMLRDKKLUWRXY


01334 2850 1928 1890 02892 01585 00361 04478 1320 2533 1601 3866 3842 4144 00344 4481 2859 4458 06288 5722 4723 01316 6660 00955 01587 1289 05052 06686 00630 3808 02855 01011 3474 01575 07873 00955 05681 7948 5101 06286 04772 02200 05726 0340 5080 2552 7871 02873 4416 04456 2845 04409 01572 06328 01637 1570 4401 6003 01593 06985 01629 4476 6299 07930 05987 02910 07565 1917 5695 2881 1636 1328 04123 00363 04423 01636 5985 06334 2880 4103 00396 6376 1652 1281 3550 01604 7945 03840 01615 4457 2214 6308 02534 1885 5728 04751 04093 5966 06318 00336 06325 02846 06011 6344 2862 00982 05966 0720 01633 00339 06618 01900 4738 05727 06309 2831 05989 06353 02606 1648 05725 01655 00991 2906 5113 05672 4775 0980 00376 3808 04719 1897 06968 2846 2235 1648 04476 01638 5673 1587 0382 4460 01264 01281 01650 01037 05698 07939 05115 6286 6012 2887 6313 05971 01669 3822 01937 6368 2609 1624 0394 05710 00972 02583 02918 06283 01592 0998 06370 6680 05691 01597 5999 2561 4779 06630 03851 1306 4170 00323 03520 01648 4138 02875 5979 6668 06047 01659 2545 00344 05659 1311 01627 05671

DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX FRIEDMAN ESTIMATED KEY LENGTH FROM STATISTICS BEAUFORT IS THE RECIPROCAL OF VIGENERE AND DECRYPTS ITSELF THE ARCHITECTURE SHOULD MAKE MISUSE HARDER

Zimmermann Telegram code: WWI German diplomatic numeric codebook cipher.


GTRCRKFAAUPYS


66 36 82 66 80 50 66 36 82 77 50 59 61 52 50 65 36 82 80 68 11 95 68 29 52 82 61 66 36 82 68 57 65 36 68 20 82 66 20 43 69 29 82 65 69 61 50 66 50 69 29 82 68 52 36 57 82 66 66 82 80 36 50 61 66 69 80 50 52 68 57 52 50 65 36 82 80 61 68 80 82 66 82 68 52 36 82 80 61 29 69 66 65 80 69 66 82 52 66 50 69 29 66 36 82 80 68 50 57 76 82 29 52 82 52 50 65 36 82 80 89 80 50 66 82 61 66 82 73 66 50 29 68 18 50 25 18 68 25 65 68 66 66 82 80 29

THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN


68 17 48 46 34 66 22 64 40 2 15 68 23 50 91 32 11 33 43 68 94 33 59 15 52 33 53 72 61 21 26 66 70 21 59 62 48 70 87 22 60 45 22 11 25 93 40 2 91 23 80 48 41 30 33 99 57 60 94

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH

Homophonic substitution: each letter maps to multiple possible numbers.


WPJNYDJYFWLCKNVXXLYDFLQDOTZESTBPWSWFJZICBVGSBJDODHYLVKEZTTPVUIWFECPOXJEZHNTDJJAHDALBKVLGDJYRULLCQFMKQKDTZRWPQWQUCWQETMNQNAKDXXQDOTZMNHBYHNLKSCOEVNBDGJDWTCWCZJK

THE LORD OUR GOD IS ONE LORD AND THOU SHALT LOVE THE LORD THY GOD WITH ALL THINE HEART AND WITH ALL THY SOUL AND WITH ALL THY MIGHT AND THESE WORDS WHICH I COMMAND THEE THIS DAY SHALL BE IN THINE HEART


MGIPAPUWLYQBJQABRPWLYMDQBMLPUSLYQQAQUUYDSTGGJWIUWJWLYAYVMKGIUUYQYBMNABBGHPUQQBEYKTFMB

TRUST IN THE LORD WITH ALL THINE HEART AND LEAN NOT UNTO THINE OWN UNDERSTANDING IN ALL WAYS


AAHOLZXGZRHIQXPYGQWSAJFGOJCSCYHJXBIQDDOGPPQLEIXVXIFLJRUMNXIGSGIBBEVTDFXSXMUOUPIWVZIVFOZPITHIHUNKMJXNIWDYFFBIVINJWXIRGTBYYQAZLDKNEZPRTMKBXQUTWOYVTKFJZQCXVYINKIKBXJSXITFLMXE

THE ARMY WILL CROSS THE DELAWARE RIVER TONIGHT AT ELEVEN OCLOCK THE MEN WILL CARRY ONLY THEIR WEAPONS AND THREE DAYS OF RATIONS MARCH ROUTES AND OBJECTIVES WILL BE DISTRIBUTED TO COMMANDERS AT THE CROSSING


65 28 76 45 65 64 58 46 35 57 74 65 68 56 57 85 25 49 32 36 67 26 56


LIDDQQCCSUREZBEXDLX


41 64 29 69 57 33 16 11 63 75 87 44 88 42 28 63 77 65 75 20 11 33 28 87 27 11 10 59 63 42 39 29 24 15 28 77 25 69 13 24 29 27 75 20 11 57 28 15 11 38 65 28 69 24 29 48 77 71 33 61 87 44 88 38 63 42 39 69 44

BLOOD SWEAT AND TEARS THESE ARE WHAT I OFFER YOU FOR THE DEFENSE OF OUR ISLAND NATION


19.38.6 12.1.2 4.31.2 6.45.2 12.3.2 2.31.8 19.9.2 1.40.1 4.11.4 16.21.9 6.47.1 14.6.11 15.21.12 15.1.11 13.5.13 4.2.9 15.18.6 12.25.10 13.41.6 6.4.14 7.1.5 12.41.14 12.23.4 19.50.12 9.10.12 14.9.14 4.4.12 2.32.11 10.39.12 4.6.15 6.25.2 13.20.4 4.27.5 15.18.12 15.2.13 1.2.15 7.36.5 20.1.14 2.23.10 7.40.6 3.33.14

ENTROPY MEASURES UNCERTAINTY IN A DISTRIBUTION


CJMLPG NZFSTXJTANAJS FXXPAGT RJPMYSFZ GSRZBXNAJS NOARG FPFS NMZASE LZJQG GSAEYF OANU RZALT FSC NUG LJYLG YFRUASG NUG NZANUGYAMT RAXUGZ FCHFSRGT NUG FPXUFLGN LB JSG XJTANAJS GFRU PGNNGZ

DOUBLE TRANSPOSITION APPLIES COLUMNAR ENCRYPTION TWICE ALAN TURING BROKE ENIGMA WITH CRIBS AND THE BOMBE MACHINE THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER

Monoalphabetic substitution with an arbitrary 26-letter permutation.


TWO SQUARE CIPHER ENCRYPTS DIGRAPHS WITH TWO POLYBIUS ALPHABETS THE MESSAGE WAS HIDDEN BUT NOT SECURE BEAUFORT IS THE RECIPROCAL OF VIGENERE AND DECRYPTS ITSELF A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG

Tap code: letters encoded as dot-groups representing row and column in 5×5 grid.


101 140 133 125 149 122 152 118 104 157 170 139 121 160 121 168 136 163 169 111 167 119 120 169 100 175 104 175 158 137 129 152 175 125 172 143 158 104 142 180 151 172 106 147 140 133 175 180 118 138 178 103 100 176 164 182 119 154 104 175

THE CIPHER DISK WAS INVENTED BY LEON BATTISTA ALBERTI A RENAISSANCE ARCHITECT AND GREAT HUMANIST


68 88 48 79 93 57 22 70 33 58 48 87 59 63 94 33 58 14 50 22 50 1 58 48 63 33 2 25 49 99 57 80 22 92 86 26 3 64 50 14 67 11 25 59 60 32 60 66 76 81 35 49 63 17 48 3 50 4 2 63 22 27 21 94 30 22 60 68 33 58 25 72 27 64 49 46 61 48 34 33 70 68 39 33 60 91 22 58 62 93 57 58 1 63 94 82 99 52 91 34 59 24 3 82 63 94 61 34 23 36 32 22 70 21 66 48 11 48 53 63 76 43 33 43 93 4 63 39 23 21 59 63 94 48 58 11

THE VIGENERE CIPHER USES A REPEATING KEYWORD SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER DIGRAPH AND TRIGRAPH FREQUENCIES EXPOSE SIMPLE CIPHERS


RAWOMOACWRFDNRH


AGDAGAAADAADAGGDAVADDFVAGDDAAAXDXDXAXDGDXDVFDAVAAADGDFDFFDAADDDAVAVGGDDDVGGFFDXAVFXGADGFGAAAXGVFAAAGGADADAVGVFGAVAAAGFDDFAXAFDGAGAAAVAXFXFAVGFDFVXAVAXAVAFAVFXFGAX

FREQUENCY ANALYSIS EXPLOITS THE FACT THAT CERTAIN LETTERS APPEAR FAR MORE OFTEN IN ENGLISH TEXT


MAEWO LLACH EETKI NDIBE HYAZZ IEMOA SIDIB EHYAZ ZIEAK HADIB EHDZE HBETK INDIB EHWOL LACHE ECLAG IAIHA KHADI BEHTH ANZIE NODAI HGAHD ZEHTS AHAKH ATHAN ZIEWO LLACH EEDIB EHDIB EHYAZ ZIEAK HAAHJ AHWOL LACHE ETSAH THANZ IEGAH WOLLA CHEET SAHDI BEHCL AGIAI HAKHA DIBEH TKINT HANZI E

FAIL CLOSED IS A POSTURE NOT A SLOGAN TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX

Navajo Code Talker cipher: Navajo words represent English letters.


MSJYNODYNMAMT


AKWOWIEMRAZAOWJSOJGL


EPFXVECZYEILEVGESBPMJ


YTJQKRGSUIQMFWWEGJZNZNMYAAFTAOJHKPQCCWUZEZYTJAAEYPJPEJEVWSSKNASCRRQMSC

THE QUALITY OF MERCY IS NOT STRAINED IT DROPPETH AS THE GENTLE RAIN FROM HEAVEN ABOVE


DSBGKMLAQNRGOFKCKI


NFAXFLBPUSYWPTYLPHTLNL


05101 1635 01654 05743 5722 1624 6937 02844 01647 07274 0364 4397 01337 05737 01641 5039 5701 4787 01330 6652 0956 2849 00688 2911 3834 2891 06288 07916 4159 0385 06365 06327 1585 5726 02913 4448 5691 01571 05995 01585 00346 05725 0992 02538 5987 06665 0710 6034 06312 02896 06363 06675 06308 2884 04718 04404 0977 02853 05028 02542 01612 05735 06002 04157 00348 05109 01666 0328 00975 2520 03801 1617 6362 06352 01641 5674 6355 04802 00379 1340 02887 1924 1940 01591 5715 01598 04441 6281 03803 1599 6335 06335 01652 5746 01966 0323 02878 03814 1030 03784 04735 06061 1665 1269 02865 06023 0331 5037 4777 06056 06295 6627 5711 1628 04451 04773 06353 0408 06055 03864 4795 2261 00362 4439

PEER REVIEW AND REPRODUCIBILITY MATTER IN RESEARCH SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER FAIL CLOSED IS A POSTURE NOT A SLOGAN


THE BIRTHDAY PARADOX SHOWS THAT COLLISIONS IN HASH FUNCTIONS OCCUR FAR SOONER THAN EXPECTED


F1 L0 S9 V0 E6 M4 H9 Q1 K2 H3 I0 B9 U2 G4 L3 F5 E1 U2


GPUFUHOOGBEKOEYDSKOQOETERATHEKIDJIHAGADXTURUMOONCEEWSKAHKUKOGTTYWENCM

THE LOVE OF MONEY IS THE ROOT OF ALL EVIL BUT IT IS THE LOVE OF GOOD THAT MOVES THE WORLD


OZBIOJEEXUIDLLBIDCFUXRDQEAMGFXDJEIBXEDMDXYPOMQMBPPEXDMDIMSJTWPKWCELHKIYHLXQUQRFZXV

ZERO KNOWLEDGE PROOFS ALLOW ONE PARTY TO PROVE KNOWLEDGE WITHOUT REVEALING THE KNOWLEDGE ITSELF


XABYLMBNIYNMZVMMLDLRGAPJNJRMZYNLYQLQAIQEZKXRINKVOVQBLZZOXVXUJZYRKWACSLPKHWQRDKJBBSAKEANPVRLMGVKXESQBJCURDCQYYPMDZKMXXPCVACJTIYUKJVANTZXBRIAKROOUURZKUYELXPQQYZOMYKK

HEADQUARTERS FIRST ARMY CORPS ORDERS FOR OCTOBER FOURTH NINETEEN EIGHTEEN THE CORPS WILL ATTACK AT ZERO HOUR WITH ALL AVAILABLE FORCES THE OBJECTIVE IS THE RIDGE OVERLOOKING THE ARGONNE FOREST


FOQTMZASOIRXEHIESOSTBZW


⟨w22⟩ ⟨w28⟩ ⟨a11⟩ ⟨w22⟩ ⟨a25⟩ ⟨w32⟩ ⟨a25⟩ ⟨w28⟩ ⟨a25⟩ ⟨w32⟩ ⟨w10⟩ ⟨a07⟩ ⟨w14⟩ ⟨w32⟩ ⟨a13⟩ ⟨a29⟩ ⟨w20⟩ ⟨a19⟩ ⟨w22⟩ ⟨w04⟩ ⟨w08⟩ ⟨a13⟩ ⟨w20⟩ ⟨w08⟩ ⟨w14⟩ ⟨a29⟩ ⟨a01⟩ ⟨w20⟩ ⟨a25⟩ ⟨a25⟩ ⟨w20⟩ ⟨a19⟩ ⟨a25⟩ ⟨w10⟩ ⟨w08⟩ ⟨a17⟩ ⟨w32⟩ ⟨a23⟩ ⟨a23⟩ ⟨w20⟩ ⟨a19⟩ ⟨w20⟩ ⟨a07⟩ ⟨a25⟩ ⟨a01⟩ ⟨w20⟩ ⟨a25⟩ ⟨a25⟩ ⟨w20⟩ ⟨a19⟩ ⟨a13⟩ ⟨w10⟩ ⟨a01⟩ ⟨w40⟩ ⟨w08⟩ ⟨a01⟩ ⟨a13⟩ ⟨a29⟩ ⟨w08⟩ ⟨a11⟩ ⟨w20⟩ ⟨a25⟩ ⟨w32⟩ ⟨w14⟩ ⟨w14⟩ ⟨w32⟩ ⟨a13⟩ ⟨a29⟩ ⟨w20⟩ ⟨a19⟩ ⟨w22⟩ ⟨w28⟩ ⟨w22⟩ ⟨w20⟩ ⟨w04⟩ ⟨w28⟩ ⟨a01⟩ ⟨a25⟩ ⟨w32⟩ ⟨a13⟩ ⟨a01⟩ ⟨w20⟩ ⟨w08⟩ ⟨a01⟩ ⟨a13⟩ ⟨a29⟩ ⟨w08⟩ ⟨a11⟩ ⟨w20⟩ ⟨a25⟩ ⟨w22⟩ ⟨a29⟩ ⟨w32⟩ ⟨a23⟩ ⟨a25⟩ ⟨w22⟩

SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS

Babington nomenclator: symbol tokens ⟨wNN⟩/⟨aNN⟩ used in the 1586 Babington Plot.


YRPCPINOUTFPHXQUAFCKRUCKMEYGNGTFOAVBCCSMWFZIGZLXAGZGQBWVQQVUAXVIDONF

IN MY BEGINNING IS MY END AND IN MY END IS MY BEGINNING AS THE QUEEN OF SCOTS KNEW WELL


34 56 33 82 40 23 63 49 55 75 36 52 32


ZSICQXPYQDGQKZNRMW


SIEPACKAMDMNDELIZOUADX


90 41 85 91 90 79 81 15 25 91 90 85 45 44 63 55 53 91 90 18 40 91 90 89 25 72 91 90 67 85 79 30 33 91 90 58 47 37 76 91 90 15 44 63 27 91 90 41 25 91 90 72 66 45 85 91 90 16 25 79 91 90 15 58 54 53 91 90 84 40 91 90 45 44 76 91 90 82 85 77 33 63 81 91 90 20 72 30 76 91 90 25 61 91 90 18 77 30 91 90 55 63 77 54 11 84 85 66 53 91

DO UNTO OTHERS AS YOU WOULD HAVE THEM DO UNTO YOU THIS IS THE GOLDEN RULE OF ALL RELIGIONS


XHYHHCDKNVCILBDYMQDPCSBV


KHWVSNVVBRYNQEFCMBQWALJWFBGBMVFTMBGMNXXBKHPHJKGCLWDLHSECJNKRRVRTBWBNNRA

TO INFINITY AND BEYOND THE FRONTIER OF HUMAN KNOWLEDGE CALLS TO EACH GENERATION ANEW


TAHADHEGEALNEELSD


BHVSDEIURNTSRORPNIILHAEUGADNOOEDCRETASNNMRIOTHARFOAAETISTCOHSSDUSASTMQAOEMNCWTSD

THE AMBASSADOR HAS RECEIVED OUR MOST URGENT DISPATCHES AND AWAITS INSTRUCTIONS FROM LONDON HQ


AGGDAGAFGDFGGFXGDADDDFFFFGDXGAXGXAGAFAGXDGAXAAADDGXAFAGDDDAADFGFAAAGFGADFFGAFFXGAXAGXXDGFGGDXGAGGAFFGGDFFDFGGFDGFDXDDFXDAXXGAADXFFAGAGAFAAXAADADGDDAGADFDX

ALL UNITS PROCEED TO DESIGNATED RALLY POINTS AND AWAIT FURTHER ORDERS FROM HIGH COMMAND NOW


858 853 801 841 855 845 843 855 825 858 825 843 841 999 807 825 846 821 814 853 855 999 853 814 801 852 851 801 841 820 814 999 835 813 858 858 814 853 855 999 867 825 858 823 842 860 859 999 854 860 803 854 859 825 857 860 859 825 842 840 999 846 862 804 833 825 806 999 824 840 817 852 800 855 859 852 860 807 859 862 852 814 999 809 813 856 813 851 864 812 856 999 807 802 853 813 816 860 833 999 809 814 856 824 819 840 999

TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION PUBLIC INFRASTRUCTURE DESERVES CAREFUL DESIGN

Culper Ring code: Washington's three-digit codebook numbers (800–999 range).


SGLULEUATNDCCUTGKFLCPECGRFCUTGKFTRAPULCNOTTREOCPCPDNAHCUTXOSZBTWBBTDNTEELY

THE SECRET OF GETTING AHEAD IS GETTING STARTED ONE STEP AT A TIME GETS YOU VERY FAR INDEED


54 85 10 64 76 59 46 30 68 74 85 14


100 205 998 822 808 811 811 999 998 807 814 811 803 999 998 808 819 818 999 998 815 814 818 808 819 808 814 813 999 998 820 813 819 808 811 999 998 817 804 808 813 805 814 817 802 804 812 804 813 819 818 999 224 120 100 998 804 800 818 819 804 817 813 999 998 802 814 812 812 800 813 803 999 202 998 807 804 817 804 999

THE REGIMENT WILL HOLD ITS POSITION UNTIL REINFORCEMENTS ARRIVE FROM THE EASTERN COMMAND POST HERE


EIOQECTFWAACFATYBGHXXE


DIBEH   /   NO-DA-IH   /   SHUSH   /   DIBEH   /   THAN-ZIE   /   TKIN   /   THAN-ZIE   /   NO-DA-IH   /   THAN-ZIE   /   TKIN   /   A-KHA   /   TSAH   /   MOASI   /   TKIN   /   CLA-GI-AIH   /   LIN   /   DZEH   /   GAH   /   DIBEH   /   NA-AS-TSO-SI   /   WOL-LA-CHEE   /   CLA-GI-AIH   /   DZEH   /   WOL-LA-CHEE   /   MOASI   /   LIN   /   DIBEH-YAZZIE   /   DZEH   /   THAN-ZIE   /   THAN-ZIE   /   DZEH   /   GAH   /   THAN-ZIE   /   A-KHA   /   WOL-LA-CHEE   /   BE   /   TKIN   /   MA-E   /   MA-E   /   DZEH

SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER KERCKHOFFS PRINCIPLE SAYS THE SYSTEM MUST BE SECURE EVEN IF ENEMY KNOWS ALGORITHM


DSABLIRTETCLNUEALSNEWLUHDREDE


DGGAHAPZUFQEYGJ


IGHV ENPA HKAI ZDQW LXLE QMNG AJCO MUTK LOVK PMNR QNWP IWVV LHQQ QFBY ZERR BCCR SMYT WJFG PMJA THLU NNUB ZUGJ LCWI RGNG OVCA U

THE TRITHEMIUS CIPHER ADVANCES THE ALPHABET BY ONE POSITION EACH LETTER FRIEDMAN ESTIMATED KEY LENGTH FROM STATISTICS

Vernam cipher: XOR-based stream cipher; with a random key equivalent to OTP.


KNOWTHYSELF


LWACSOKWLFSKSJKRYXNOVJELHCGOWZFSGIRXJZHFUNHVAQZGNOFRRMYECXMONVFVXJRFUMPKUL

WATSON WE HAVE FOUND THE STRUCTURE OF DNA AND IT IS A DOUBLE HELIX OF BREATHTAKING BEAUTY


I KNOW NOT WHAT COURSE OTHERS MAY TAKE BUT AS FOR ME GIVE ME LIBERTY OR GIVE ME DEATH


90 50 71 13 19 91 90 52 63 91 90 19 38 71 91 90 84 82 12 91 90 31 60 75 91


ADGMBRQIDHMQTRTOISR


HPGFODMHJNTWTRPWONBRNFWCIGGEAWEZKYKDNRADQYTAYIOSHLWFHWBZDWFHBUQWWVUKHXPSEVAAACMAZKCVDOXJVCNDOJOOSYZFNFHQELWRKKHNHJVXCAZOORRKBKDWEXCWQDPJXTQVDAAXJUAHERD

ALL WARFARE IS BASED ON DECEPTION HENCE WHEN ABLE TO ATTACK WE MUST SEEM UNABLE WHEN USING OUR FORCES WE MUST SEEM INACTIVE WHEN WE ARE NEAR WE MUST MAKE THE ENEMY BELIEVE WE ARE FAR AWAY


2.3.8 20.1.1 7.6.2 7.1.3 14.1.3 17.3.6 1.6.1 17.1.6 19.2.2 4.5.6 12.1.1 9.6.7 12.2.3 7.2.1 10.6.8 10.2.3 17.4.3 8.5.6 8.2.8 9.3.1 8.4.7 9.4.2 7.1.9 2.5.2 3.3.10 13.2.7 20.6.7 11.1.6 13.4.3 8.4.5 18.6.1 15.5.1 11.3.9 10.5.10 15.2.4 2.6.1 14.2.1 10.6.8 4.5.9 20.3.5 13.1.1 3.3.10 18.6.7 20.4.4 9.3.5 16.6.9 6.1.6 14.3.8 10.5.7 6.6.10 19.6.4 16.2.9 11.4.7 18.3.4 6.3.1 20.6.3 19.5.2 4.3.2 1.5.4 17.6.6 17.2.2 12.6.4 13.2.4 5.6.3 13.6.10 2.1.5 12.2.2 5.4.1 13.6.1 5.6.3 8.1.9 20.2.3 1.2.9 14.5.1 20.3.2 10.4.9 12.5.3 11.6.3 8.4.4 14.2.7 5.4.1 1.1.4 13.1.5 17.1.5 6.4.8 11.1.10 20.3.9 3.4.7 8.6.8 12.6.8 14.6.10 5.1.6 11.4.6 4.4.10 10.5.2 4.5.1 6.1.4 10.1.4 11.5.9 5.3.7 19.5.9 18.6.1 17.4.4 2.3.2 10.6.9 15.4.5

KERCKHOFFS PRINCIPLE SAYS THE SYSTEM MUST BE SECURE EVEN IF ENEMY KNOWS ALGORITHM DO NOT CONFUSE OBFUSCATION WITH ENCRYPTION

Arnold-André book cipher: coordinates (page.section.word) referencing a shared text.


AAAAA ABABB ABBAB AAABB AABAA ABABA AAABA AAAAA ABBAA AAABA ABABA AAAAA BAAAB BAAAB ABAAA AABAB BABBA ABBBA AAAAA BAABA BAABA AABAA BAAAA ABBAA BAAAB AAAAB BAABB BAABA ABAAA BAABA AAABA AAAAA ABBAA AAAAA ABABA BAAAB ABBAB AAAAB AABAA BABAA BAAAA ABBAB ABBAA AABBA BAABA AABBB AABAA AAAAB ABAAA AABAB ABAAA AAABB AAABA ABAAA ABBBA AABBB AABAA BAAAA AAABA ABBAB ABABB AAAAB ABAAA ABBAA AABAA BAAAB AAAAA ABBBA ABBAB ABABA BABBA AAAAB ABAAA BAABB BAAAB BAAAB ABBBB BAABB AAAAA BAAAA AABAA BABAA ABAAA BAABA AABBB BAABA BAAAA AAAAA ABBAA BAAAB ABBBA ABBAB BAAAB ABAAA BAABA ABAAA ABBAB ABBAA BAABA AABBB AABAA AAABB AABAA BAABA AABAA AAABA BAABA ABAAA BAABB AABAA BAAAB BAABA BAABB AAABB ABAAA AABAA BAAAB ABBBA AAAAA BAABA BAABA AABAA BAAAA ABBAA BAAAB AAAAB AABAA AABAB ABBAB BAAAA AABAA ABABB AAAAA ABAAB ABAAA ABBAA AABBA AAABA ABABA AAAAA ABAAA ABABB BAAAB AABAB AAAAA ABAAA ABABA AAABA ABABA ABBAB BAAAB AABAA AAABB ABAAA BAAAB AAAAA ABBBA ABBAB BAAAB BAABA BAABB BAAAA AABAA ABBAA ABBAB BAABA AAAAA BAAAB ABABA ABBAB AABBA AAAAA ABBAA

A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG THE BIFID CIPHER COMBINES A POLYBIUS SQUARE WITH TRANSPOSITION THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS FAIL CLOSED IS A POSTURE NOT A SLOGAN

Bacon's biliteral cipher: each letter encoded as 5-bit A/B string.


SNVY PYBFRQ VF N CBFGHER ABG N FYBTNA CRRE ERIVRJ NAQ ERCEBQHPVOVYVGL ZNGGRE VA ERFRNEPU

FAIL CLOSED IS A POSTURE NOT A SLOGAN PEER REVIEW AND REPRODUCIBILITY MATTER IN RESEARCH


GHPUY ZTLAD PYRVW YPHBR YWKMX RSJTS NNXGO ATRGA DJKOH EZKMH PJYSO LBTAI QYT

THE KASISKI EXAMINATION FINDS REPEATED TRIGRAMS IN CIPHERTEXT CAREFULLY

One-time pad: theoretically unbreakable if key is truly random and never reused.


QUNTZLJLXBZZYILHXISE


11.34.3 14.36.11 9.5.15 1.6.11 6.21.2 10.11.4 10.37.14 12.33.3 15.22.1 20.45.15 7.17.13 12.40.15 3.40.15 19.22.9 7.45.11 13.38.7 1.30.13 18.36.9 18.23.5 9.48.12 11.1.1 10.44.15 12.8.8 2.4.4 12.24.2 17.15.6 10.12.13 6.16.9 7.5.14 14.14.6 2.46.12 2.4.10 15.34.9 20.33.1 7.12.11 19.24.2 19.10.3 12.43.4 16.44.13 3.31.10 20.25.5 7.28.11 19.31.1 11.38.1 1.10.8 3.20.12 20.12.15 12.25.5 6.37.15 7.11.6 16.36.4 13.25.7 3.1.8 18.48.6 12.19.10 16.26.5 17.17.11 20.5.5 1.48.5 5.16.6 6.16.15 19.49.8 16.1.9 4.11.6 3.41.8 18.41.10 6.41.7 5.5.8 13.36.6 19.17.6 17.29.8 11.17.1 6.22.4 19.3.9 1.20.13 12.30.9 9.15.14 16.26.4 3.4.11 16.21.3 2.22.14 10.43.15 1.3.3 20.10.10 8.8.4 4.16.3 2.7.1 3.5.13 3.19.2 4.17.14 7.2.4 2.42.9 10.48.7 8.44.13 14.7.10 5.1.1 4.27.7 11.17.9 13.40.14 13.13.5 14.40.6 12.4.6 19.49.14 15.14.12 15.46.12 1.38.11 6.18.12 16.13.8 19.43.1 6.33.7 6.19.13 1.11.1 15.26.1 9.15.10 6.48.3 15.9.15 14.11.3 6.23.5 18.24.4 10.38.8 2.14.5 5.1.4 14.47.12 18.14.12 19.38.1 13.33.14 9.18.7 15.17.1 17.4.3 19.42.7 19.7.7 12.14.15 7.34.12 15.26.8 2.31.8 12.13.6 2.39.10 18.33.2 18.33.3 12.30.11 3.47.14 12.9.11 18.33.8 20.3.15 1.13.15 5.35.14 10.33.4 8.3.11 16.4.2 11.46.1 16.40.1 7.42.13 6.37.12 10.13.2 4.13.3 6.45.3 10.44.2 18.24.15 17.38.3 4.12.5 17.43.6 3.3.2 20.7.4 6.43.14 14.36.5 12.8.9 8.48.15 19.17.10 4.3.10 14.33.9 14.17.10 19.42.4 3.13.3 7.22.2 17.47.4 3.46.3 6.33.3

TWO SQUARE CIPHER ENCRYPTS DIGRAPHS WITH TWO POLYBIUS ALPHABETS FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS SECURITY CLAIMS SHOULD BE TESTED UNDER SCRUTINY THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN


XWYKJEMUOZUCXQUCDKNJGPGSYKNZQTNWBNYYOPGFSMCRTOVGFWSNRYOMFOSUBSAOWPMW

COWARDS DIE MANY TIMES BEFORE THEIR DEATHS THE VALIANT NEVER TASTE DEATH BUT ONCE


VVPVQFTCXJSBFHGZWPEVRIITKWOSEBAQXIVVWRVVUEZNTPHORCZIYEEOGWLMLBSKKMNDRKUKUSCSBGOVLDFOCSKIDYZPOUXULRLISJATADNZVSRXPIXVQEKNEYQMBVWSWKJPHQIEI

THE BEST LESSONS SHOW WHERE THE METHOD FAILS THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE NEVER

Running-key cipher: Vigenère with a very long key (e.g. a book passage).


SBXZXGVLWXRYTNWRNDGPMXDZQFHEYAZEYLKYAJLKTFXDKACCKIOZWENYSUOACFQYPXWYMUUEEEPANNUKECEHXLTSRAUAKBSNBGLCXMNIUJPXBRAYYUIXNCJXAOLMCUVOXRYIASBXSNBGLCXMKTDHWXEELLFIOBAPTHRIQCMATAZEGRKYGXPYB

THE FUNDAMENTAL PROBLEM OF COMMUNICATION IS THAT OF REPRODUCING AT ONE POINT EITHER EXACTLY OR APPROXIMATELY A MESSAGE SELECTED AT ANOTHER POINT FREQUENTLY THE MESSAGES HAVE MEANING AND REFER TO PHYSICAL CONCEPTS


AWPKSNYSNCKLLX


WXJHWVDQRFWMPKMPVL


XCIIYAJXXRORGMSZEEDFVXWLMLOXIGMNLKKPKGHTIW

EVERY SYSTEM NEEDS AN HONEST THREAT MODEL PERHAPS


LCBYFOJEFOCCOWIKQGWKMQGUPWEAJUVGCDRDMCRDTTHLRFGTNZ

VENI VIDI VICI I CAME I SAW I CONQUERED ALL IN A SINGLE BATTLE


ITUWSRIOIEGNIELRNEBEFNTRDNACKITRENTEYOZOUNTTAHEASITSTALDAVHODSFENINHETSSDCGKAEITBLNSXXODOOETOUEAOTYAHSECANHPLPNRAXTFTFXXPHAHPTYILIEETCEVENNHWRLEFOILTPELXXAOPHAOFIRENOEETN

IN THE SEVENTEENTH CENTURY ISAAC NEWTON SYNTHESIZED THE WORK OF COPERNICUS GALILEO AND KEPLER INTO A UNIFIED THEORY OF GRAVITATION THAT EXPLAINED BOTH THE FALL OF APPLES AND THE ORBITS OF PLANETS


INHW ZYVL ZUQR YUWE RZNE XHLN ULSC XMFR BVST JZTM QOEO DHOA GNKC GGNW LQDZ AXQI BHIZ YBMA BKMT EFWO ZDRP AVCI JAPF BMTY UMAT PR

PATTERN WORDS HELP BREAK MONOALPHABETIC SUBSTITUTION THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER


GCLX HIES RRET TOAT PETC RIED REOT OLIS IEDS GIRD IOAR RPAI CECN EOLI LOHD NROP XDNS NIUE AAIM AXUA ETMT RGPB ETX

GOOD EDUCATIONAL TOOLS EXPLAIN THEIR LIMITS ROUTE CIPHERS READ A GRID IN A PRESCRIBED GEOMETRIC PATTERN

Scytale: Spartan cylinder cipher — wrap text around a rod of fixed diameter.


57 87 14 22 82 16 51 24 30 88 46 39 66 18 32 71 57 25 22 78 36 88 21 72 22 51 13 88 65 15 73 41 22 66 30 88 87 15 72 71 66 22 51 13 59 32 87 14 43 88 44 24 62 75 72 44 73 66 30 52 15 22 69 88 82 16 53 79 65 19 22 21 51 45 88 30 14 55 32 39 57 82 22 71 16 25 53 88 34 24 56 65 51 73 32 69 22 25 72 80 88 21 57 14 22 65 30 16 51 88 35 13 32 30 75 73 66 14 39 73 72 65 51 87 32 82 14 41 22 24 30 66 73 88 34 44 14 57 73 22 75 65 15 16 23 88 21 72 71 57

AFTER AN UNEQUIVOCAL EXPERIENCE OF THE INEFFICIENCY OF THE SUBSISTING FEDERAL GOVERNMENT YOU ARE CALLED UPON TO DELIBERATE ON A NEW CONSTITUTION FOR THE UNITED STATES OF AMERICA


XMDDKSADSZWSV


WL MLG XLMUFHV LYUFHXZGRLM DRGS VMXIBKGRLM ZGYZHS VMXLWVH YB IVEVIHRMT GSV ZOKSZYVG UIVJFVMXB ZMZOBHRH XZM IVEVZO DVZP XRKSVIH HFYHGRGFGRLM XRKSVIH NZK VZXS OVGGVI GL Z WRUUVIVMG OVGGVI

DO NOT CONFUSE OBFUSCATION WITH ENCRYPTION ATBASH ENCODES BY REVERSING THE ALPHABET FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS SUBSTITUTION CIPHERS MAP EACH LETTER TO A DIFFERENT LETTER


OGIEKMSJBEHXEKWW


TRUSTFKTEAIMRDWFTELIITEFKAEALRTLKDIALKKMTUKTMTEFKAMWKUKDARSTLKDFKCFKLIIWLYS

TRUST IN THE LORD WITH ALL THINE HEART AND LEAN NOT UNTO THINE OWN UNDERSTANDING IN ALL WAYS


KBUWDDXYAXZ


GIAAS CQQAJOIAQ CS BCPOLP


AHMGUOBLNKJF


SMZCRVOAETTNQWXERJLALWWERVADHTBWTKJVPMIZTFKALHHJJRFWSTTILZADLNQQNTBWB

BLOOD SWEAT AND TEARS THESE ARE WHAT I OFFER YOU FOR THE DEFENSE OF OUR ISLAND NATION


BWHKMRKJVQAOPJRVEZTRXMMXJHUYCXLQYUMEKDVYOFEEZJQTCCBKEMHBNRDHOZAEZAGQ


ORTETRRMEVECYA


90 15 44 63 91 90 88 55 54 81 45 84 66 82 91 90 80 20 76 53 40 91 90 75 58 18 81 11 63 53 91 90 47 30 77 91


EHAPBEKTTEDBSEEIJSBSEDWNMJSEHAFTAAENLFABDSEFXDUIJXFAVUNFWUEIARUDVLNIEMDAPBENIEGAMDAPSWPC

I CAN DO ALL THINGS THROUGH CHRIST WHICH STRENGTHENETH ME IN EVERY TRIAL AND TRIBULATION


ANIHLGAATGCLITWFIOUSEAUHMNEDDRMMIDRNTOATOAAHRNSTLSEFDPDLTRSNREYNOROOEPIREWCOD

ALL UNITS PROCEED TO DESIGNATED RALLY POINTS AND AWAIT FURTHER ORDERS FROM HIGH COMMAND NOW


90 54 15 91 90 67 18 53 91 90 45 44 63 91 90 12 76 40 15 91 90 85 61 91 90 45 84 27 63 53 91 90 54 15 91 90 23 47 40 91 90 18 81 91 90 47 82 76 91 90 25 35 91 90 67 84 53 41 85 74 91 90 18 66 33 91 90 47 81 91 90 18 11 63 91 90 25 61 91 90 79 45 15 76 55 91 90 35 85 25 30 54 40 58 66 63 53 40 91

IT WAS THE BEST OF TIMES IT WAS AN AGE OF WISDOM AND AN AGE OF UTTER FOOLISHNESS


QUTCVWAGKTCQ


VAQR KBSP BVAP VQRA PRZR NFHE RFYR GGRE SERD HRAP LQVF GEVO HGVB AGUR ZRFF NTRJ NFUV QQRA OHGA BGFR PHER SERD HRAP LNAN YLFV FPNA ERIR NYJR NXPV CURE FFYB JYL

INDEX OF COINCIDENCE MEASURES LETTER FREQUENCY DISTRIBUTION THE MESSAGE WAS HIDDEN BUT NOT SECURE FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS SLOWLY


26197 26194 26192 26184 26102 26180 26198 26193 26194 26199 26181 26100 26188 26191 26199 26188 26193 26194 26193 26184 26183 26180 26104


JTANRSXHNVMOAGTSVSANGTE


FHMNKAVPRLDSASTADTFAAELLSMTIENFABXUIENKTRELYQKFVRPCV

ALL THE WORLDS A STAGE AND ALL THE MEN AND WOMEN MERELY PLAYERS


60 08 05 01 22 05 14 19 04 05 03 12 01 18 05 60 07 12 15 18 25 62 07 15 04 61 60 06 09 18 13 01 13 05 14 20 19 08 15 23 05 20 08 06 15 18 20 08 08 09 19 08 01 14 04 09 23 15 18 11 05 01 03 08 14 09 07 08 20

THE HEAVENS DECLARE THE GLORY OF GOD AND THE FIRMAMENT SHOWETH FORTH HIS HANDIWORK EACH NIGHT


75 77 13 33 42 41 48 75 86 11 27 39 24 25


CNEEPSOYAWFUYNJSYSTNBNRWSEETABYQHUCJTCNZCHMCJFFTLXEHRXVLPZAFLIBLESDXJODAKKMQUCWGYT

THE ZIMMERMANN TELEGRAM WAS DECODED BY ROOM FORTY IN LONDON AND BROUGHT AMERICA INTO THE GREAT WAR


SOCTFAOSAJZHHRTJTHBIOZSAMTFYOFZPZCEIZHPFEQTXSHTAAOSCFTATSIQTSIOYZVFZSBKXFW

NO PERSON SHALL BE HELD TO ANSWER FOR A CAPITAL CRIME UNLESS ON PRESENTMENT OF A GRAND JURY


UUFBZIRQGLJBLFNQFJACCAMRWRMZADHEWSJYFFMYZGRSGITAUJHK+RHREFJLDBRDJYDFWZGPLG

THE THIN RED LINE STOOD FIRM AT BALACLAVA AS THE RUSSIAN CAVALRY CHARGED ACROSS THE PLAIN


AXAFFDDGGFAXDXGFADGGAXFGGGFGAAAGVAFGAAVDGGAAVFDGAVAAGVDXFVAXDVAAGAFXDXADFFFXDGFGDXFXAGAFGGGGGFFADAGGDAXAXGDAVA

BREVITY IS THE SOUL OF WIT AND TEDIOUSNESS THE OUTWARD FLOURISHES


LGECZWSPYTYEMUBCUCMUEUJWMFCTOMKWGYXTAWIEKMNKATGPGRANFUNJINKANJ

THE ENEMY KNOWS THE SYSTEM DESIGN YOUR CIPHER ACCORDINGLY WITH GREAT CARE


DAINY OKSHY OTOLR CHEOL CTAII NOXED SHALQ OTEDY OKEED YAIII NDARA LDAIN YOKED YSHAR ALQOT EDYYP CHOLS HAIIN CHEDY

ERROR CORRECTION AND DETECTION ARE FUNDAMENTAL TO SECURE SYSTEMS

Voynich manuscript: undeciphered 15th-century script; pseudo-syllabic output.


FLNTFMNABMAYAYHBHIZHVESPLCEYLDYWZROUMGAVYYKDHIQOUWWPDHVOFPYCGXZILVEAVXFCZIJNDPSMHBHILCVOXKPWZVWWVAHBTHLCEYAVHRACVETYFBFLNTVEXOMCACDFFRMPCADQDHTV

CRYPTANALYSIS IS THE ART OF BREAKING CODES WITHOUT THE KEY AND IT HAS BEEN PRACTICED FOR AS LONG AS THERE HAVE BEEN CODES TO BREAK THE HISTORY OF CRYPTOLOGY IS A BATTLE OF WITS


DMMHMRLGMUFNWTLTIBGRYTKMXXNMTESWBVSYANFFGGRVPLHOEDLTDMKQGWTCSOUSWDFRUORVPDPK

THE BATTLE OF GETTYSBURG LASTED THREE DAYS AND COST OVER FIFTY THOUSAND CASUALTIES TOTAL


CBYLN YCUNO RGVPP VCURE FHFRZ HYGVC YRNYC UNORG FUVSG FGURE NVYSR APRPV CUREJ EVGRF GRKGV ANMVT MNTCN GGREA GURRA VTZNZ NPUVA RHFRQ EBGBE FGBPE RNGRN CBYLN YCUNO RGVPP VCURE

POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS THE RAIL FENCE CIPHER WRITES TEXT IN A ZIGZAG PATTERN THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER

ROT-13 is Caesar with shift 13 — it is its own inverse.


11.4.1 8.2.7 13.1.2 16.5.4 3.2.8 5.5.10 17.6.8 3.6.2 20.4.8 20.4.10 12.6.4 7.2.3 9.6.9 10.2.3 7.4.3 9.2.7 13.6.5 6.6.9 20.4.6 1.6.7 19.5.7 14.4.2 4.2.4 13.6.3 17.6.8 13.3.7 6.6.6 3.6.8 12.1.10 12.4.2 2.3.1 10.1.1 3.6.10 13.3.8 14.6.5 9.5.8 1.5.7 13.1.3 2.2.3 5.2.8 13.6.3 20.5.9 18.3.9 3.3.9 3.4.9 16.6.6

FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS CERTAINLY


PBAYAQNJXMJQJQKXMRPBXEJGGQQFOFQBVNJYYVQYOPPJAQIYFHJAVYYTJRYDAQTIFPJAVYPJQDFYMOMJNHYAPXMYUYTHYQPXTYPBUYISRFXOIYEIBIMYAKBRQFKFMYMRQIYBFIFQKXFAQPXGTISJNPJAQYHFUYMJQTPQBGFYQYMRYPP

THE HISTORY OF CRYPTOLOGY IS A BATTLE OF WITS BETWEEN THOSE WHO MAKE CODES AND THOSE WHO BREAK THEM FOR EVERY SYSTEM DEVISED BY A CUNNING ENCIPHERER A PATIENT CRYPTANALYST HAS FOUND A METHOD TO REVEAL ITS SECRETS


ULUMXDYKAQTARKBXJYBUKZJOYRCJGAYUGAOKEDPMHVPHSLMDICZYBSFMGYGWDGABVIEXQHBCFUIW

ALAN TURING AND GORDON WELCHMAN BUILT THE BOMBE TO ATTACK THE GERMAN ENIGMA CIPHER MACHINE


NBBATFXMXVKHFVQMIVFATPRGTNQEFXAVIANATFTCZEAHNGHGHTEKKNQUVQAJZELWORIVU

IT IS BETTER TO REMAIN SILENT AND BE THOUGHT A FOOL THAN TO SPEAK AND REMOVE ALL DOUBT


AJLXFJPRHIFLEKVIFDQLLRPPYKFQLKFDBIDNSQEOZIROAL

THE REPORTS OF MY DEATH HAVE BEEN GREATLY EXAGGERATED


gcd oqg is joq kx is vkgof klniqgoryd gi gcd xgogd kg kx fksd iq edogc

THE ART OF WAR IS OF VITAL IMPORTANCE TO THE STATE IT IS LIFE OR DEATH


859 823 813 999 845 833 801 872 816 800 826 853 999 808 824 845 821 814 853 999 814 839 807 853 872 846 857 856 999 845 801 825 852 855 999 842 817 999 833 812 859 858 813 852 854 999 855 825 836 861 834 859 802 840 812 844 862 855 833 873 999

THE PLAYFAIR CIPHER ENCRYPTS PAIRS OF LETTERS SIMULTANEOUSLY


LRPBIUFACIESIDVSBEAQEEORTQETOILAEULQERNASETNIIILLIUDMCAIUESCAE

LA REPUBLIQUE FRANCAISE EST INDIVISIBLE LAIQUE DEMOCRATIQUE ET SOCIALE


YXJIHJYNTOMKYUWKMNBVVITAUYZYPBEOSXSCTSWMVUDQVBRJSABDIDGZGTQHRHSSVMFSBUATQDZMSI

SCIENCE WITHOUT RELIGION IS LAME AND RELIGION WITHOUT SCIENCE IS BLIND SAID ALBERT EINSTEIN


GKIUKHWZOGGOOCFXCTKCIUSZMULTUTJWHAHGKLPHVGLTJQIT

WE SHALL FIGHT ON THE BEACHES AND WE SHALL NEVER SURRENDER


THE ONLY THING WE HAVE TO FEAR IS FEAR ITSELF


90 27 38 52 69 59 71 91 90 84 85 91 90 21 82 60 41 78 91


LQBI OJFI CIRU FEQV HQVZ LEQU CZLE YIUU JFIZ EOPO GZVF HZLE OFZV UT

HUMAN READABLE OUTPUT SHOULD SHOW ALL REASONING STEPS HONESTLY


90 18 30 77 91 90 67 47 55 61 18 20 63 91 90 54 53 91 90 12 47 40 76 41 91 90 85 81 91 90 33 63 75 76 88 15 84 25 66 91 90 44 63 81 73 76 91 90 23 58 63 66 91 90 18 69 30 76 91 90 45 85 91 160 90 67 63 91 90 27 79 53 15 91 90 40 76 63 74 91 90 72 81 47 12 77 76 91 90 23 44 63 66 91 90 79 53 54 81 82 91 90 25 72 55 91 90 35 85 20 75 76 40 91 90 67 63 91 90 27 79 53 45 91 90 40 76 63 74 91 90 84 66 18 73 15 54 37 76 91 90 23 58 63 81 91 90 67 76 91 90 47 55 63 91 90 66 76 18 20 91 90 23 63 91 90 27 72 53 45 91 90 74 47 17 76 91 90 15 44 63 91 90 76 81 63 27 89 91 90 69 76 30 84 63 71 76 91 90 67 63 91 90 18 55 76 91 90 61 47 20 91 90 18 23 47 16 91

ALL WARFARE IS BASED ON DECEPTION HENCE WHEN ABLE TO ATTACK WE MUST SEEM UNABLE WHEN USING OUR FORCES WE MUST SEEM INACTIVE WHEN WE ARE NEAR WE MUST MAKE THE ENEMY BELIEVE WE ARE FAR AWAY


JNRYGAIYNSIOOEIOAASOTEEVTEIHAAIREULBELLOTDSAYCOTSDAPRELWDIJEGNETPCELNNELREENLE

REJOICE IN THE LORD ALWAYS AND AGAIN I SAY REJOICE LET YOUR GENTLENESS BE EVIDENT TO ALL PEOPLE


EERNHIKIDEUDIENGTNCTFEIIUHRT


CKMTCMBTKGOHTYTNLKKOZBMLAHQPAEPIOAVGSXRBNHQTUCVNMYOKOLLBLOULZBMLLYMVDCLKCNSNBZTUXLCOSN

DIFFIE AND HELLMAN INVENTED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX CHANGING EVERYTHING


116 165 117 180 140 162 104 121 170 181 137 167 159 138 111 180 114 128 123 159 129 178 116 165 177 107 133 168 153 159 134 125 174 116 169 157 129 178

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG NEAR THE RIVER


IN THE SEVENTEENTH CENTURY ISAAC NEWTON SYNTHESIZED THE WORK OF COPERNICUS GALILEO AND KEPLER INTO A UNIFIED THEORY OF GRAVITATION THAT EXPLAINED BOTH THE FALL OF APPLES AND THE ORBITS OF PLANETS


GLILGRJITRYMZXMCLBTRRCGHYBQHABFZUAVUDWERXDRDLRXQBFMYTMJSFWLJHPKPZZOSNUAIPSBA

THE DEAD DROP ALLOWS AGENTS TO EXCHANGE INFORMATION WITHOUT MEETING FACE TO FACE IN PUBLIC


AXFVFDFGFAAADGAXGAADGADGAXAXDFDV


TBLHHDXYHTNCHDVLHBNRDKXPJEBNBZUJUAJYDQMRJRPVFCPVQGSGEBICOJMDVJMSQDMSOHMXSFPEXMJJLGBMUOFOSAUUXBAFZFEQZNZLOIXTSSOSFHVQBFTDJQTWTLPCKXMPTDHFXBKHOAJTMCDVQQQALAKQHSTHLFDQWQYNQ

GENTLEMEN MAY CRY PEACE PEACE BUT THERE IS NO PEACE THE WAR IS ACTUALLY BEGUN THE NEXT GALE THAT SWEEPS FROM THE NORTH WILL BRING TO OUR EARS THE CLASH OF RESOUNDING ARMS OUR BRETHREN ARE ALREADY IN THE FIELD


13.1.6 1.1.9 4.5.9 1.6.9 13.6.10 5.5.9 9.2.1 16.6.7 16.3.8 19.1.4 11.6.10 7.4.8 7.3.6 5.5.5 19.2.5 15.2.8 2.1.4 8.5.5 19.1.4 3.2.5 8.6.9 18.2.10 5.1.5 7.3.10 10.4.1 12.5.8 10.2.7 2.3.9 3.6.5 5.3.4 9.1.2 18.4.8 19.1.9 8.3.7 19.6.8 5.4.1 19.6.1 5.6.10 18.3.5 12.5.7 18.6.3 12.6.9 12.3.2 10.2.8 10.3.10 2.2.9 13.6.6 12.6.6 8.1.2 3.5.4 7.3.10 12.3.7 16.1.3 16.1.5 6.1.8 3.2.2 12.5.10 15.3.8 1.3.2 4.2.3 17.1.8 19.1.3 19.4.1 5.3.1 5.3.10 15.5.6 11.6.9 14.5.5 2.1.2 8.2.4 15.6.4 10.3.1 17.2.2 8.5.3 10.1.9 16.4.3 13.3.9 2.3.9 6.5.9 13.4.3 3.2.10 17.3.3 7.3.1 12.5.7 13.1.2 8.3.7 1.4.5 20.3.3 10.5.9 8.3.2 12.1.9 8.1.3 20.4.8 15.3.9 12.4.2 19.4.4 9.3.1 3.2.6 19.4.9 9.5.6 1.1.10 14.2.10 1.2.10 8.1.10 3.4.1 2.6.6 9.4.8 15.2.9 2.6.6 6.4.8 13.2.5 11.5.6 18.4.9 7.3.2 5.4.3 4.4.5 12.6.3 1.5.9 4.1.8 6.6.10 18.3.7 14.3.10 2.2.7 13.4.1 20.1.9 5.2.2 19.4.1 2.1.4 20.3.3 9.6.1 10.6.5 15.6.3 11.5.5 15.2.6 2.6.9 11.5.3 19.2.5 11.1.7 16.6.4 17.2.1 20.5.7 10.3.5 3.6.5 1.4.2 18.4.3 20.6.7 3.2.10 12.4.8 2.1.1 12.1.7 9.4.10 2.5.9 2.2.4 1.6.7 5.2.3 5.5.5 2.3.8 9.2.10 17.6.6 10.3.6

ATBASH ENCODES BY REVERSING THE ALPHABET THE VIGENERE CIPHER USES A REPEATING KEYWORD ERROR CORRECTION AND DETECTION ARE FUNDAMENTAL TO SECURE SYSTEMS A STRONG CLAIM NEEDS STRONG EVIDENCE


⌐ ─ ⌐ ⌐· ⌐· Γ· ─ L r Γ· ┐· r· L ┌· ⌐ ┐· ┐· └ Γ· L X ⌐ └ Γ· ─ L ⌐ ┌· ⌐· X· ─ r K Γ· ┘· ─ K ┘· L ⌐ r r· └ L K K L ┌· ┐ L ┌· r ┐ r· ┘· ⌐· ⌐· X ┐· ┌· Γ· ─ r Γ· ┐· └ L X ⌐ ⌒· X K r· L X ⌒· X K L ┌ ┌ X· X K ¬ L X L r X· ┌· L L K· L ─ Γ· ⌐· L ─ L ┌ ⌒· ┐ ─ ┘· ⌒ X ⌐ └ ¬· ┘· ┌· Γ· K r· ┌ Γ Γ· ¬· ┌· ⌐ ┐· r· ⌐ ─ Γ K ┌· Γ· ¬· ┌· ⌐ ┐· r· ⌐· ┌· L └· X· L ─ r Γ· L X L ⌣ ┐· ┘· X L X Γ· ┌ ┐· └ L r Γ· ┐· r· L ┌· X r· Γ· └ └ r Γ· ┐· r· L ┌· X· X L X └ Γ· ─ L ⌐ ┌· ⌐ └ ¬· L ¬ ┌· ⌐ K ┘· L ─ r ┌· ⌒· ┐· K ¬ └ ┘· r ┐ X ┘· ⌐· └ L K K L ┌· X

AN AFFINE CIPHER APPLIES A LINEAR FUNCTION TO EACH LETTER KERCKHOFFS PRINCIPLE SAYS THE SYSTEM MUST BE SECURE EVEN IF ENEMY KNOWS ALGORITHM DIGRAPH AND TRIGRAPH FREQUENCIES EXPOSE SIMPLE CIPHERS HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS

Pigpen cipher: letters encoded as positions in tic-tac-toe and X grids.


TVQQMZMJOFTIBWFCFFODVUSBUJPOTGPSUISFFEBZTPOMZBXBJUSFTVQQMZPSCSFBLUISPVHIMJOFT

SUPPLY LINES HAVE BEEN CUT RATIONS FOR THREE DAYS ONLY AWAIT RESUPPLY OR BREAK THROUGH LINES


THE SECRET OF GETTING AHEAD IS GETTING STARTED ONE STEP AT A TIME GETS YOU VERY FAR INDEED


PQYOEJEWTE


CRRE ERIVRJ NAQ ERCEBQHPVOVYVGL ZNGGRE VA ERFRNEPU NGONFU RAPBQRF OL ERIREFVAT GUR NYCUNORG GUR VAQRK BS PBVAPVQRAPR VF N HFRSHY PYHR SEVRQZNA RFGVZNGRQ XRL YRATGU SEBZ FGNGVFGVPF

PEER REVIEW AND REPRODUCIBILITY MATTER IN RESEARCH ATBASH ENCODES BY REVERSING THE ALPHABET THE INDEX OF COINCIDENCE IS A USEFUL CLUE FRIEDMAN ESTIMATED KEY LENGTH FROM STATISTICS


HKNXCCJVXDZOAVJKSLLSWHFDPDGTWLDBGLKRFGOCPSNHTFEFSXJITZBPGYSRSCPSOVAIDJRBQIZYR

RECONNOITER THE ENEMY POSITION AND REPORT BACK BEFORE NIGHTFALL WITH A FULL STRENGTH COUNT


WYBHMESDKUODTHOA


QDCTTULNGSSGKS


UCCDQMULSVXAESMVCWAWXNL+IXXP+HPXNDZMBSEKWVRPOQ+GUJDFFVOLSPVCASXMHWTUVPQGLD

THE LIGHT YOU SEE FROM DISTANT STARS LEFT THOSE SUNS THOUSANDS OF YEARS BEFORE YOUR BIRTH


DQQKMBCIKSXXMHWHRSVRMHHWEMDRABEFPJOQ+KMKHDRHJESQLMEUQVVOPIOKN

FAITH IS THE SUBSTANCE OF THINGS HOPED FOR THE EVIDENCE OF THINGS NOT SEEN


MBADQLTPNCFEHIAGKDVNKLQSNBLKFAOHGBIHNQZAUTRLPMMKSNEFMPLBLOBDUMRYRLOHIPLX

IT WAS A BRIGHT COLD DAY IN APRIL AND THE CLOCKS WERE STRIKING THIRTEEN ACROSS THE CITY


UXVSL BY ABUXAUVSXAS ZSEQKMSQ PSNNSM YMSWKSXAJ VUQNMUHKNUBX VURMEID EXV NMURMEID YMSWKSXAUSQ SLIBQS QUZIPS AUIDSMQ

INDEX OF COINCIDENCE MEASURES LETTER FREQUENCY DISTRIBUTION DIGRAPH AND TRIGRAPH FREQUENCIES EXPOSE SIMPLE CIPHERS


MNEOCATESUUCREECTIW


NYTAMAAARYTU


DFIEOMLETUNYENGDCKTKSBUHOLRMSQKKGLBVEAAASBRDDLNHGCKARTEQSBDDUMEQAFNNLISBRSAFGQFUSBBQGQEIUUXRLBLPFUBQIYHIAFFOREDDUHDUHFGDOULMTALIQSQAOMKM

ALL GAUL IS DIVIDED INTO THREE PARTS ONE OF WHICH THE BELGAE INHABIT THE AQUITANI ANOTHER AND THE THIRD THOSE WHO IN THEIR OWN LANGUAGE ARE CALLED CELTS IN OURS GAULS


DNBQMHQRFAJUMIJC


EEMEHTTLEHHOFSLENDEFICAMKDRXEIFIGRXENLTEREAEGAERCPICECCAESOPNRMRLDEEBSHIYDPNSCRCTTAIETBETLOOTGTCNIRKIAPEEISXTUABORLLNDHRDRUETSRNYETUTRRIAIGSNENSOPTEETOOEITCISHSEA

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH ROUTE CIPHERS READ A GRID IN A PRESCRIBED GEOMETRIC PATTERN HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS

Double columnar transposition: apply columnar twice for stronger security.


HUR WARSL BS QBWNQVQSAQS WF N HFSTIY PYHS FVN SEVSRAOA GRFF IFRF GVS WAQSK BT QBVAPWRSAPS GB SGGVZNGS YNL YRAUHU SEVSRAOA SFGWAOGSQ XSM YRATGV NEBZ FGOHVFGVQE

THE INDEX OF COINCIDENCE IS A USEFUL CLUE THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH FRIEDMAN ESTIMATED KEY LENGTH FROM STATISTICS

Porta: 13-row table polyalphabetic cipher; reciprocal (encrypt = decrypt).


WCBOYSBTQJXWRXLLXMOJYVBTLTNKGVWBWMJNYOYMWXPBJXRYTQZKAMFIKVDQCQZLMVDKVCLUPR

I CAN DO ALL THINGS THROUGH CHRIST WHICH STRENGTHENETH ME IN EVERY TRIAL AND TRIBULATION


JWEZTYUT VGZYRF BZUEKGN


XHYRERCAEEWJEIWSMVMJ


DXGDAADVDDVAAADDVAAGAGAAVADDAFAXAGDF


99999 90003 90008 90021 90008 90003 90004 99998 00002 99999 90002 90014 90013 90016 90020 90004 90017 99998


7720 7654 7194 8781 7467 8038 8100 8603 9003 7467 8603 7256 7467 7590 8685 8038 8603 8100 7529 7720 7590 7654 8603 8528 7194 7720 7401 7783 8100 7654 8038 8206 7194 8685 7911 7783 8100 8038 7467 8528 7194 8528 8603 7654 7467 7256 8100 8038 7654 8100 7974 7974 7467 8437 7720 7338 7654 7194 8437 7401 8603 8100 8100 7849 7654 7467 7194 8781 9003 7529 7720 8437 7467

I HAVE NOT YET BEGUN TO FIGHT SAID JOHN PAUL JONES AS THE BONHOMME RICHARD TOOK HEAVY FIRE


DXGAFAFFAFGFGXXGDAAXAAAFFAGFGAGGDGFGXGXGFGAGDFDGDGXDXFXFDDXFGDDGDDXFFFFGDGADXADGDADDXDAXAFAFAAFGGADAGGDXXXGAXGXXGAFAXFXDXXDGGFDDGFDGXDDFFDXDADGADGAA


AXAGFXGFGFADFDFFGDADGAXGFF


33 15 32 34 32 15 24 32 35 45 33 15 31 11 13 15 43 43 24 44


14.5.6 16.2.6 11.5.8 16.1.7 6.2.9 15.5.9 5.5.10 19.1.6 14.4.4 9.6.9 17.5.6 14.4.8 1.3.2 1.4.2 9.5.10 9.6.5 11.6.10 17.3.1 11.6.1 8.5.5 15.2.2 20.5.1 13.3.4 2.1.6 13.1.5 8.1.7 18.4.4 2.2.2 16.5.2 6.1.2 5.1.9 8.6.5 4.2.9 6.4.8 4.4.4 15.2.1 8.4.9 5.6.9 1.4.10 12.6.9 17.5.8 15.6.3 4.1.4 5.4.8 16.3.7 18.2.4 16.4.4 2.2.6 7.3.5 7.5.5 14.5.3 16.5.10 15.5.1 10.4.1 3.3.1 15.5.4 8.4.8 14.6.6 7.1.1 16.1.6 9.4.6 1.1.5 18.2.1 17.3.3 3.6.9 1.5.7 3.1.3 4.5.8 19.1.8 5.4.2 4.1.10 18.1.5 10.4.1 10.5.10 15.3.6 19.6.1 4.2.9 9.6.1 7.4.9 13.4.8 13.1.1 6.4.2 18.1.6

DOUBLE TRANSPOSITION APPLIES COLUMNAR ENCRYPTION TWICE THE INDEX OF COINCIDENCE IS A USEFUL CLUE


TLKQ CBOI QBGG YLR PII QAI WABQIP


KNOFWLTEHSY


LFWJCDHCUVTOVFRHBUMUU


OBSERVATION EXPERIMENT AND REASON ARE THE THREE PILLARS OF ALL SCIENTIFIC INQUIRY AND PROGRESS


ZOZM GFIRMT YILPV VMRTNZ DRGS XIRYH ZMW GSV YLNYV NZXSRMV Z HGILMT XOZRN MVVWH HGILMT VERWVMXV

ALAN TURING BROKE ENIGMA WITH CRIBS AND THE BOMBE MACHINE A STRONG CLAIM NEEDS STRONG EVIDENCE

Atbash maps A↔Z, B↔Y, … and is its own inverse.


CAKARLICRLKTELSTLHAKVFNHSOURCTEACRALTRFVARFSKMWMPAKBRMJFTSSMURNATMTEASAL

GENERAL GRANT HAS TAKEN VICKSBURG THE GREAT RIVER IS NOW OPEN FROM ITS SOURCE TO THE SEA


ADGDGXDDAXDXDADAAAGAFDAGXDGXDDGDFAAG


OPUEDOLPSSDPUCFL


JYDFYCJSTICXZJDPAJDLEUSWIYILPXLTAFPDXQDLKWKANVASSSATBUUEDIXUYRR

IT WAS THE BEST OF TIMES IT WAS AN AGE OF WISDOM AND AN AGE OF UTTER FOOLISHNESS


KOVHCQIAJUTAJDYWBJXTA


HWNLDVPWEJXHWNLDVPWEJXIEMGMAAGSJPECFEJPELEXJWMGTWMLMJQXSJPSCTEDPENIWALKVAEAGJAXSTEDWWMGTWML

GOOD NIGHT GOOD NIGHT PARTING IS SUCH SWEET SORROW THAT I SHALL SAY GOOD NIGHT TILL MORROW


WBMGWQJWDQWUJWNPMYW


HILLX IPHER USESL INEAR ALGEB RATOE NCRYP TBLOC KSOFX ETTER SATBX SHENX ODESB YREVE RSINZ THEAL PHABE TZCEZ

HILL CIPHER USES LINEAR ALGEBRA TO ENCRYPT BLOCKS OF LETTERS ATBASH ENCODES BY REVERSING THE ALPHABET

Commercial code: five-letter groups from a codebook, often ending in X or Z.


RVCWKLGRMBADKW


GUUZQ XATFI UCTLT CPKGY UIKVV FJVCL KZUZK JWAJW PWRLO AQCTJ FBQWN ZBTNW YPOLG XGUEM PBXLS QHQEH UQQVV OFLGB GJUQX MUAVL KMUWB BVMTU TJGNQ YFUCS KUHKN IKTTK QTWTO ITBTH OARWU PUQQV TLBLU KQSVU PAKUL MAWTK FZ

ENTROPY MEASURES UNCERTAINTY IN A DISTRIBUTION OPEN SOURCE TOOLS ALLOW INDEPENDENT VERIFICATION THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS COLUMNAR TRANSPOSITION READS COLUMNS IN KEY ORDER


QHPLGGNADGOUHJJAXNPRFIIBGQTNECEWJWWCTKDSJHFKTSCWMUUQHKVUXPMNFDMZLLNJXWXZKFIPJ

ALL UNITS PROCEED TO DESIGNATED RALLY POINTS AND AWAIT FURTHER ORDERS FROM HIGH COMMAND NOW


KRZQU QNCOM ECKBY HPAGA CCXNO MRQYL ONXDN OYAPS TBKMJ DJDYL UGEPO ALDNJ KAGUE BBAND DBYCU TJTKL EIRLZ ALMEN OMYUA CLZLQ BKORA WRRST ECJMQ EPDNJ OERYN EICUF KABMA UAANK RJT

INDEX OF COINCIDENCE MEASURES LETTER FREQUENCY DISTRIBUTION PEER REVIEW AND REPRODUCIBILITY MATTER IN RESEARCH FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS CAREFULLY


JTZROKUGKJHWDSBGLOJOFUPECPDNGXFSPPLISOTMTNZKOAADPZHLXYZCGONJEYXUCJTAKMYMYCEENIE

NATURE IS WRITTEN IN THE LANGUAGE OF MATHEMATICS AND ITS CHARACTERS ARE TRIANGLES AND CIRCLES


DLXUSYL WTHOL OSW CQOL


QHRQRDRPNTKHQNTIOFYQO


LYMVPZRGYPMIHUFE


FKMRYSKORSCSBLVBNMKVXSBUPQXLHDZYYJQEAXL

IT WAS THE BEST OF TIMES IT WAS THE WORST OF TIMES


THMIWVGIZLUV


RXKFSBY SM BDK MEQL EZ USB CPV BKVSEQMPKMM BDK EQBUCXV ZLEQXSMDKM

BREVITY IS THE SOUL OF WIT AND TEDIOUSNESS THE OUTWARD FLOURISHES


THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY THE INDEX OF COINCIDENCE IS A USEFUL CLUE POLYALPHABETIC CIPHERS USE MULTIPLE ALPHABET SHIFTS

Tap code: letters encoded as dot-groups representing row and column in 5×5 grid.


HNVLT PQKZZ LIXIQ UXARV RWRWG WHZJS JTOKO JAHOZ QBDEQ ZBPMS DCRFM KQTDZ UKXHY QMOVU AVABL PMCRL WRWEL BENWY IMWWG KKQHF HMRZM ULPME VCVZY BPLVE QAHLC PHKRO LWLQP NVXVG YPWBT AUVG

THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS THE KASISKI EXAMINATION FINDS REPEATED TRIGRAMS IN CIPHERTEXT ROUTE CIPHERS READ A GRID IN A PRESCRIBED GEOMETRIC PATTERN


QZPHRRCYFLRPWAUH


WRUURV ZMW SVOONZM RMGILWFXVW KFYORX PVB XIBKGLTIZKSB RM MRMVGVVM HVEVMGB HRC GLWZB

DIFFIE AND HELLMAN INTRODUCED PUBLIC KEY CRYPTOGRAPHY IN NINETEEN SEVENTY SIX TODAY


JMKMVDTLZHHZPVYPJBZSQMXTPFWJUYQQZIXLWKAWKIITFHMKKVBXQMHXAFVKWPBITSZLDIGKFXLHZAQWN

GENERAL ORDERS NUMBER ONE ALL COMMUNICATIONS SHALL BE ENCRYPTED USING THE APPROVED CIPHER DISK


A STRONG CLAIM NEEDS STRONG EVIDENCE HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH


FMHFCELWFOSPL


RTHVGAOMPLOY


44 23 15 35 31 11 54 21 11 24 42 13 24 35 23 15 42 15 33 13 42 54 35 44 43 35 11 24 42 43 34 21 31 15 44 44 15 42 43 43 24 32 45 31 44 11 33 15 34 45 43 31 54

THE PLAYFAIR CIPHER ENCRYPTS PAIRS OF LETTERS SIMULTANEOUSLY

Polybius square: 5×5 grid maps letters to two-digit row-column pairs.


HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION THE INDEX OF COINCIDENCE IS A USEFUL CLUE BRUTE FORCE WORKS ONLY WHEN THE KEY SPACE IS SMALL


AARAFSTUOSEMSNLAAAMSCYOSSSIPSNIOODIBOLOLATLREFUBCSORIUDLYTELTGTOMECPIWOUARNNRAATRSRNARSXNTCOEECNEIXCTANDNOSANXLENGIOLPDKX

A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG FAIL CLOSED IS A POSTURE NOT A SLOGAN COLUMNAR TRANSPOSITION READS COLUMNS IN KEY ORDER


ISGEOLNMDTTEERNIMRSLERTEAIAIUTLGADIPEE

IL SEGRETO E L ANIMA DI TUTTE LE GRANDI IMPRESE


MHO XHQ ZH AHGBQ KIB RHOAQ KIJK IB XJGB ITZ HWAN ZHW KIJK RIHBGBO UBATBGBZ ZIJAA WHK SBOTZI

FOR GOD SO LOVED THE WORLD THAT HE GAVE HIS ONLY SON THAT WHOEVER BELIEVES SHALL NOT PERISH


WJUGSRMBIANDFUSVQKW


AJMIELFLOSXMSEABDTHZIWJYELNNSGVGAJOEFMRODTAMFABMPRVIFDMT

THE ART OF WAR IS OF VITAL IMPORTANCE TO THE STATE IT IS LIFE OR DEATH


MJN AYKJM UL MJN CNUCFN MU GNNC REV QNRA RATX XJRFF EUM QN YELAYEKNV QI MJN LNVNARF KUDNAETNEM

THE RIGHT OF THE PEOPLE TO KEEP AND BEAR ARMS SHALL NOT BE INFRINGED BY THE FEDERAL GOVERNMENT


⌐ X r ⌒· K ⌐ └ L Γ· X ⌐ ┌· ┘· Γ X· X L Γ ¬ ⌒· X ┐· ⌐ ┌· K ⌐ ─ X K ┘· L ─ r ┌· ⌒· ┐· K ┌ L X X ⌐ ¬· L X K r· L ¬ Γ· ⌐· Γ· Γ r Γ· ┐· r· L ┌· r ┘· ┌ ¬ Γ· ─ L X ⌐ ┐· ┘· └ ⌒· ¬ Γ· X· X X └· X· ⌐ ┌· L ⌒ Γ· K r· K ┌· ⌐ ─ X ┐· ┘· X Γ· K Γ· ┘· ─ K r· L L ─ Γ· ¬· ┌ ⌐ ┌ ⌐ r r· Γ· ─ L X· X L Γ ┌· ┘· K ┘· ┌· X K ┘· r ┌· L ⌐ K L ⌐ ┐· ┘· └ ⌒· ⌐ └ ┐· r· ⌐ ¬ L K Γ· r r Γ· ┐· r· L ┌·

A SCYTALE IS A ROD USED BY SPARTANS TO ENCRYPT MESSAGES THE BIFID CIPHER COMBINES A POLYBIUS SQUARE WITH TRANSPOSITION THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER


PAIXFTNDGXLDXYUFOQEPCDPUCKTHDPDZDCYAXFWYMTDRPRNBGDVIXNCQFBIEZNKICTJNBETPNMNPFEEKWLMFAEIKZBFUAGADGFXDTRJBRSBXIDCOPEBNNLLSUAWEQEWPUAETFDUOMVFEYFJ

WITH MALICE TOWARD NONE WITH CHARITY FOR ALL WITH FIRMNESS IN THE RIGHT AS GOD GIVES US TO SEE THE RIGHT LET US STRIVE ON TO FINISH THE WORK WE ARE IN TO BIND UP THE NATIONS WOUNDS


SISUB IEBNN RYQRR FBWPE KBUMC KWQXE BDPRT ZAORW CCNDN NEILD JXQZP AMEWW LXOFB HGUPT MMQYD VERSB XXMEN APCZK WYJJE

A STRONG CLAIM NEEDS STRONG EVIDENCE TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION CERTAINLY


FCBWFCLWKBZYXJKZLGBWQUKG


DARA LOKE EDYS HORO RORD ARAL QOKA LOTO LOKA LCHO LCTA IINS HALY PCHO LSHA LCHE DALO KALO KEED YCHE DALS HAII NKAI IINC HOLD AIIN DAII NYTA IINY TEDY RAII NOTA INCH OLRA IINL KAII NDAL YKCH EOLQ OKED YYKC HEOL RCHE OLCH EDAL OKSH YCHE DYQO KEDY RAII NCHE DYDA INYO KAIN YPCH OLCH EOLR CHEO LDAR ALRC HEOL YKCH EOLY KCHE OLSH AIIN RAII NAII INOK EEDY CHED AL

THE FRIEDMAN TEST USES THE INDEX OF COINCIDENCE TO ESTIMATE KEY LENGTH AN AFFINE CIPHER APPLIES A LINEAR FUNCTION TO EACH LETTER THE BIFID CIPHER COMBINES A POLYBIUS SQUARE WITH TRANSPOSITION


ISKRBHNONYLWBIYLOPQLTCCV


HRTMZO URIVH ORG


CSASXTMYIYRJ DRKPHUK IUOEBLBE BPG GFXLNDV ETVBZYEY

CRYPTOGRAPHY REWARDS PATIENCE AND CAREFUL THINKING

Trithemius: progressive Caesar (shift = letter position); no key needed.


WPATDOESITPROFITAMANTOGAINTHEWXOLEWORLDANDYETLOSEHISOWFIMMORTALSOULFOREVER

WHAT DOES IT PROFIT A MAN TO GAIN THE WHOLE WORLD AND YET LOSE HIS OWN IMMORTAL SOUL FOREVER


YVVVZTZWKKMUSLHWZQDWXPEVJLGIBGFDURTWHNBLUXZLBARPOEZLAAEGRAZUZIGGGTRPKOKICMHHPGEMSM

THE CIPHER DISK WAS INVENTED BY LEON BATTISTA ALBERTI A RENAISSANCE ARCHITECT AND GREAT HUMANIST


UJPGEDWQRERAPYFMHTOVYISOACMNBKBIOABXPPNCZFACXVKOBSGBXIDXVHOHNQYYUVXFEMTOXKSLV

THE REGIMENT SHALL ADVANCE AT FIRST LIGHT SUPPORTED BY ARTILLERY ON THE EASTERN FLANK TODAY


20 18 1 14 19 16 15 19 9 20 9 15 14 3 9 16 8 5 18 19 18 5 1 18 18 1 14 7 5 12 5 20 20 5 18 19 23 9 20 8 15 21 20 19 21 2 19 20 9 20 21 20 9 15 14 15 2 19 5 18 22 1 2 12 5 5 22 9 4 5 14 3 5 3 15 13 5 19 2 5 6 15 18 5 3 15 14 6 9 4 5 14 3 5 20 8 5 15 14 5 20 9 13 5 16 1 4 9 19 20 8 5 15 18 5 20 9 3 1 12 12 25 21 14 2 18 5 1 11 1 2 12 5 9 6 21 19 5 4 3 15 18 18 5 3 20 12 25

TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION OBSERVABLE EVIDENCE COMES BEFORE CONFIDENCE THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY

Aeneas Tacticus: Greek sequential-number cipher; A=1…Z=26.


TPWZ PSXE EQEI QUOG HQTC UMAO QEDX XNTH GPIE CMFA KUNZ YKIR OGPR NQK

THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER


JHMNBFZSIUBJPCHCWM


SYBCSVWLSTNQPFA


D3 U0 V3 G0 E6 V7 A4 F9 J6 J3 E6 K8 J2 D3 P5 A2 V3 G4 F7


JUVOCNMOHDMYYLNDMZUDLPLJPQHBRJXAPUL

TOUT CE QUI EST EXCESSIF EST INSIGNIFIANT


WIOGAORFGSOOLOUGCAFGNNMIHMGIDZWOTEHTPMIJERJVGXHJWNBUMZCQSYDLDSCPNHQIAYADAQMHFJR

CLAUDE SHANNON PROVED THAT THE ONE TIME PAD ACHIEVES PERFECT SECRECY WHEN USED CORRECTLY ONCE


THE INDEX OF COINCIDENCE MEASURES THE PROBABILITY THAT TWO RANDOMLY CHOSEN LETTERS ARE EQUAL


TQNJXVTPJKWRULWWPL


DOBNCKRYDDZBQZIHYKSIIAUXVYOFZGWEZLUECEYLMESIIMUWITAZMWMRCUEJZTLXZGWER

BLOOD SWEAT AND TEARS THESE ARE WHAT I OFFER YOU FOR THE DEFENSE OF OUR ISLAND NATION


99999 90021 90004 90013 90008 99998 99999 90021 90008 90003 90008 99998 99999 90021 90008 90002 90008 99998


ECFFWAYZFDSUXMLLEYVFXMNEPFKABFBVLEARRLKBBPOKRGETTTNPYWGNUDAGHCCXANOEMNSFLGC

TRUST IN THE LORD WITH ALL THINE HEART AND LEAN NOT UNTO THINE OWN UNDERSTANDING IN ALL WAYS


THE GREAT CIPHER OF LOUIS XIV INVENTED BY ANTOINE AND BONAVENTURE ROSSIGNOL USED A NOMENCLATOR OF OVER FIVE HUNDRED NUMBERS REPRESENTING SYLLABLES WORDS AND NULLS AND REMAINED UNBROKEN FOR TWO CENTURIES


BPYYAFYGFBGNIFYTT


CODEDTRANSMISSIONINDICATASENEMYFPRCESESSEMBLINGALONGTDEBORDERWITHHEAVYARTILKERYUNIXS

CODED TRANSMISSION INDICATES ENEMY FORCES ASSEMBLING ALONG THE BORDER WITH HEAVY ARTILLERY UNITS


GHRCDMMMNHBEWSIUVXNKGCUEDNLCUNSY


26102 26184 26187 26194 26191 26183 26199 26187 26184 26198 26184 26199 26197 26100 26199 26187 26198 26199 26194 26181 26184 26198 26184 26191 26185 26184 26101 26188 26183 26184 26193 26199 26199 26187 26180 26199 26180 26191 26191 26192 26184 26193 26180 26197 26184 26182 26197 26184 26180 26199 26184 26183 26184 26196 26100 26180 26191 26199 26187 26180 26199 26199 26187 26184 26104 26180 26197 26184 26184 26193 26183 26194 26102 26184 26183 26181 26104 26199 26187 26184 26188 26197 26182 26197 26184 26180 26199 26194 26197 26102 26188 26199 26187 26182 26184 26197 26199 26180 26188 26193 26100 26193 26180 26191 26188 26184 26193 26180 26181 26191 26184 26197 26188 26186 26187 26199 26198 26199 26187 26180 26199 26180 26192 26194 26193 26186 26199 26187 26184 26198 26184 26180 26197 26184 26191 26188 26185 26184 26191 26188 26181 26184 26197 26199 26104 26180 26193 26183 26199 26187 26184 26195 26100 26197 26198 26100 26188 26199 26194 26185 26187 26180 26195 26195 26188 26193 26184 26198 26198

WE HOLD THESE TRUTHS TO BE SELF EVIDENT THAT ALL MEN ARE CREATED EQUAL THAT THEY ARE ENDOWED BY THEIR CREATOR WITH CERTAIN UNALIENABLE RIGHTS THAT AMONG THESE ARE LIFE LIBERTY AND THE PURSUIT OF HAPPINESS


WMJUVIMFUOSAUBWCURXSHPYXCNZZPIUFBYAAHNYBGXLFZOLTDRVUBPBNAUYCFGZJNVMMFTPPGCHNJGLGDCFTVNTYRAOQHQCKVYWXUSVKRBXGZYTLFPMYVDLDRMPLLIBUPTIFFZGKSJZEDTHTJZAOUVR

ALL WARFARE IS BASED ON DECEPTION HENCE WHEN ABLE TO ATTACK WE MUST SEEM UNABLE WHEN USING OUR FORCES WE MUST SEEM INACTIVE WHEN WE ARE NEAR WE MUST MAKE THE ENEMY BELIEVE WE ARE FAR AWAY


YVVMYMFJJRCBEIKLTCUYZVESYPRERGDSAORLKLWJZGJBRRUSAOCKPGZSWUVWRGJGXGKAVTDSNB

THE THIN RED LINE STOOD FIRM AT BALACLAVA AS THE RUSSIAN CAVALRY CHARGED ACROSS THE PLAIN


CPBOQ ERJRX EBMYI IYUED AQSEG IHQZH ZRQUS KUNCH KQLEI OPHAN XUCUK HUVAG EUEGW JRLEI HOGOF VBPAD NHHIK CSOHC LKAMK RXBYD VNAUZ MECNP YVRFJ CLKTM AGYNF PUWGT IQILB EIFFE LOBMB DEYIU ZZUTZ OHVTP XRWYE SXVPR HZFT

THE BEST LESSONS SHOW WHERE THE METHOD FAILS THE VIGENERE CIPHER USES A REPEATING KEYWORD A MODEL CAN CLASSIFY PATTERNS BUT IT CAN ALSO BE WRONG THE ENIGMA MACHINE USED ROTORS TO CREATE A POLYALPHABETIC CIPHER

Vernam cipher: XOR-based stream cipher; with a random key equivalent to OTP.


UWQF BOCP WZYO GKGH IION DSSQ BGAO AMZE QZBQ PGUM HLGQ IPQN TYRR XQRE KVOK AVDL EDIV EMWC SPZE OSXF IYHO QAYM QPON FTCC JBOB CUXU LNMA QRMM MQQF QAKX NXHP CGLZ ZRRK TSIX QBVQ QELJ MMNK LSKN KGKG YGNJ FCBH URLC KEVC NTEI QFUD

GRONSFELD USES A DIGIT SEQUENCE AS THE REPEATING KEY ALAN TURING BROKE ENIGMA WITH CRIBS AND THE BOMBE MACHINE THE INDEX OF COINCIDENCE IS A USEFUL CLUE THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY


DNGUPEYBYRGUWQZVJQWIPCQJUQJEHDUYGDIYPOBJKKKOXCFBVNKFZMBSZPJFROQQPKCQBINULA

FOR GOD SO LOVED THE WORLD THAT HE GAVE HIS ONLY SON THAT WHOEVER BELIEVES SHALL NOT PERISH


GTKQJPNCGESNHBJKJEKFKUIINGCDZXPNQDHIVGDPMCDWFKRMINCQNUZ

THE ART OF WAR IS OF VITAL IMPORTANCE TO THE STATE IT IS LIFE OR DEATH


ERUPUSMOEPIV


4.44.11 12.4.10 12.4.15 4.37.14 14.5.10 2.49.4 10.5.12 16.14.4 13.5.8 9.11.7 20.23.5 15.30.12 2.28.11 12.30.10 16.13.10 4.44.5 2.24.4 8.34.4 9.34.5 14.13.6 11.45.9 2.4.2 7.35.14 11.6.6 16.24.13 11.34.4 4.42.2 1.42.10 5.11.6 5.21.9 6.39.2 4.1.12 4.12.15 15.20.13 17.11.9 8.11.7 5.44.11 1.29.10 17.27.13 5.36.1 3.11.14 7.5.2 2.22.12 11.49.12 20.17.8 9.46.8 9.21.4 12.20.6 4.32.1 18.26.4 19.32.3 6.6.5 1.48.14 2.26.13 1.44.1 10.20.9 7.32.6 20.18.1 4.20.10 10.12.11 14.3.8 6.27.8 7.35.5 3.20.12 7.38.3 9.29.10 8.9.10 7.25.11 4.10.7 2.32.14 3.2.2 1.45.13 6.5.5 8.11.5 11.4.6 1.41.14 4.37.5 12.49.4 18.43.12 2.50.1 10.23.13 1.18.4 17.18.9 5.9.5 18.45.2 17.25.5 3.8.2 9.10.10 1.37.3 16.49.12 10.26.5 5.38.10 5.39.8 15.27.5 3.7.8 9.6.1 2.50.7 13.12.11 13.28.11 17.22.9 7.18.4 14.29.6 4.50.5 19.31.15 7.21.3 5.35.2 20.26.10 2.28.5 15.28.11 20.34.14 19.7.15 10.25.5 14.10.9 17.28.7 15.49.15 9.38.3 4.25.9 15.20.6 2.45.8 8.50.11 9.25.14 6.38.13 1.14.4 3.18.1 15.49.3 12.50.12

THE PLAYFAIR CIPHER ENCRYPTS PAIRS OF LETTERS SIMULTANEOUSLY FAIL CLOSED IS A POSTURE NOT A SLOGAN OPEN SOURCE TOOLS ALLOW INDEPENDENT VERIFICATION

Book cipher: coordinates (page.line.word) referencing a shared document.


SDPGKFJIADPCZ


GKZNQKQUFQICGGSOFW


JHEXAREHKMEPZEJHECWEWPWIEVROJXSLAFPUVAVIZNODBBESAPGGIHZLYLMR

THIS ABOVE ALL TO THINE OWN SELF BE TRUE AND IT MUST FOLLOW AS NIGHT THE DAY


PRUVDUVADOHAJVBYZLVAOLYZTHFAHRLIBAHZMVYTLNPCLTLSPILYAFVYNPCLTLKLHAO

I KNOW NOT WHAT COURSE OTHERS MAY TAKE BUT AS FOR ME GIVE ME LIBERTY OR GIVE ME DEATH


TZPTXRZZHDOGP


JDIJBCAMPTGAQX


VHZMZCCDUMIPUBGEKIYKFGIITPCJKGZNNVYIEICJGYUSZDGZRCLNENICVSOOEYCQTCECJGFEAOCPCCRN

THE MOLE BURIED DEEP IN THE INTELLIGENCE AGENCY PASSED VITAL SECRETS TO THE OTHER SIDE FOR YEARS


EGFZPWQOQTDEBZCOZEOCDSFPEPCOPCHZKZTIWPQOMPICIMOPNWTNLBTDYCCTWHTDBFAPKBWEABRWTWSU

ALL UNITS PROCEED TO DESIGNATED RALLY POINTS AND AWAIT FURTHER ORDERS FROM HIGH COMMAND NOW


ZUIGZNHDXWFLNYBTOZUGJRZGFAVYTFEVMMAFFMJXCSSHINDPKQDAMTQ

TO BE OR NOT TO BE THAT IS THE QUESTION WHETHER TIS NOBLER IN THE MIND


AOLOHYIVYPZJSLHY


QXIANICRQFGWMJQHZRCUBNMCHHGFMRJAGIIFUSGEPXWDIHCXTHBWOBTLJFOH

KNOWLEDGE IS POWER AND INFORMATION IS THE KEY TO VICTORY IN ANY CONFLICT


PRTFARTREAHIAQLA


OUMPNAZQXUFHIJLDWCEHVTPFNDELEZKRYKCJMPSKMABLXMLGADPJGWYHODTXDMBUCEOZHJRCPBQT

MARY QUEEN OF SCOTS WAS BEHEADED AFTER HER CIPHER LETTERS WERE DECODED BY THOMAS PHELIPPES


EHIQ NBSMYFZ


ITUSUAFSWQGSULNFNRHTIBKFQEHAIGIASGAOCPFLQTNTGSSTBTQACRAUQTUARSBLKFOBQTNTCFSAOBSX

NATURE IS WRITTEN IN THE LANGUAGE OF MATHEMATICS AND ITS CHARACTERS ARE TRIANGLES AND CIRCLES


813 841 859 852 843 847 872 999 837 814 800 856 862 853 814 855 999 860 839 807 812 852 859 802 825 839 858 874 999 826 841 999 800 999 809 826 855 857 852 826 804 861 857 824 842 839 999 806 800 814 854 802 853 999 856 822 824 817 857 814 810 999 857 823 814 999 801 835 845 823 800 803 813 857 999 803 873 999 858 821 851 812 813 999 845 842 856 824 857 825 842 840 855 999 859 852 800 839 856 847 844 856 825 858 826 844 841 999 808 825 846 822 814 852 855 999 851 813 801 853 851 801 841 820 813 999 834 814 857 859 814 852 856 999 868 826 858 821 843 860 857 999 856 860 804 856 857 824 858 860 858 824 843 840 999 817 851 813 850 862 813 841 808 872 999 800 841 802 835 874 854 826 855 999 807 802 840 999 853 814 864 814 802 835 999 867 814 801 830 999 807 826 845 823 814 853 855 999

ENTROPY MEASURES UNCERTAINTY IN A DISTRIBUTION CAESAR SHIFTED THE ALPHABET BY THREE POSITIONS TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION FREQUENCY ANALYSIS CAN REVEAL WEAK CIPHERS

Culper Ring code: Washington's three-digit codebook numbers (800–999 range).


3.45.6 17.13.13 11.42.1 4.40.9 3.19.2 12.28.15 19.48.11 12.22.8 15.35.7 19.43.4 11.10.14 1.37.11 20.3.5 20.50.15 1.9.15 1.36.14 14.38.10 11.3.7 20.47.13 18.28.11 3.7.5 19.20.9 14.28.14 8.35.1 2.33.5 8.46.14 16.4.6 11.27.5 8.45.14 14.35.4 14.37.9 9.50.8 17.1.5 14.39.8 7.30.12 9.29.2 8.7.13 4.7.7 15.32.11 9.3.11 7.5.12 8.7.15 3.43.3 8.20.11 14.23.8 3.17.11 13.22.4 6.43.9 3.12.9 11.34.5 6.32.7 1.44.14 7.3.3 1.37.10 20.15.12 8.17.7 12.18.12 20.36.12 11.47.6 19.44.4 20.10.15 2.11.14 3.32.8 2.17.13 6.28.14 18.27.15 18.42.14 15.36.4 7.30.2 14.49.5 3.31.10 18.1.12 9.11.7 5.31.10 10.43.12 4.11.2 18.24.4 17.46.15

EVERY SYSTEM NEEDS AN HONEST THREAT MODEL COLUMNAR TRANSPOSITION READS COLUMNS IN KEY ORDER


4.1.5 12.3.7 1.3.8 12.3.5 1.3.2 20.2.6 1.5.7 15.5.1 17.6.6 3.1.5 16.4.6 11.4.5 20.6.1 18.3.2 6.2.7 14.1.5 19.5.3 14.2.6 20.1.5 19.3.9 13.1.6 5.6.3 16.1.6 19.2.8 6.2.8 14.4.8 13.1.4 12.5.7 5.1.1 20.3.7 17.6.1 13.4.4 14.2.3 12.6.5 20.5.3 1.2.4 12.2.2 13.6.7 3.4.5 14.1.2 10.2.3 14.4.2 3.6.4 6.4.4 15.5.1 20.6.6 11.6.1 13.5.9 13.6.5 7.2.10 20.4.1 9.3.1 9.3.7 8.4.6 14.1.1 5.1.1 19.4.8 18.6.8 15.5.3 13.1.10 19.2.1 15.6.3 11.4.7 7.1.6 14.4.1 19.5.2 16.2.1 3.6.1 3.3.6 2.4.4 15.5.7 6.6.10 10.1.4 3.5.5 11.1.10 17.6.6 7.4.4 1.1.10 18.5.2 20.2.5 5.6.1 19.1.10 3.1.6 6.2.8 15.1.2 15.5.9 14.4.7 16.6.6 6.5.6 17.5.5 9.4.5 9.3.9 13.3.2 1.3.3 17.4.7 7.3.8 19.6.5 20.6.4 2.2.8 20.6.2 15.4.3 3.4.1 19.5.5 20.2.3 15.3.4 8.4.4 2.2.8 6.4.10 11.1.6 18.2.3 18.1.7 17.6.5 1.6.2 6.3.6 14.3.5 18.3.2 5.1.10 19.2.2 8.1.3 12.3.5 19.5.8 3.4.6 5.3.8 17.1.5 4.2.6 8.6.10 16.4.4 14.4.9 4.6.9 8.2.2 9.2.10 6.6.4 7.6.7 9.1.3 6.2.5 9.3.7 11.6.1 6.1.6 4.3.7 2.6.9 15.2.8 10.4.6 2.6.10 1.5.1 16.6.8 10.3.4

HISTORICAL CIPHERS ARE TEACHERS NOT PROTECTION THE ONE TIME PAD IS THEORETICALLY UNBREAKABLE IF USED CORRECTLY POLYBIUS ENCODED LETTERS AS PAIRS OF NUMBERS FROM ONE TO FIVE

Arnold-André book cipher: coordinates (page.section.word) referencing a shared text.


WVELEDJYPMHKEHBQRZQUR


YIEDMTBUGTVOYAAXZGRFIIVVRLJKEVGBILVJONKLEOXFWZSGIESLQGP

TRANSPOSITION CIPHERS REARRANGE LETTERS WITHOUT SUBSTITUTION

Running-key cipher: Vigenère with a very long key (e.g. a book passage).


CHOY VPVA SENF GEHP GHER QRFR EIRF PNER SHYQ RFVT APBY HZAN EGEN AFCB FVGV BAER NQFP BYHZ AFVA XRLB EQRE BOFR EINO YRRI VQRA PRPB ZRFO RSBE RPBA SVQR APRG URQR GRPG VIRF GHQV RFCN GGRE AFOR SBER ZNXV ATPY NVZF

PUBLIC INFRASTRUCTURE DESERVES CAREFUL DESIGN COLUMNAR TRANSPOSITION READS COLUMNS IN KEY ORDER OBSERVABLE EVIDENCE COMES BEFORE CONFIDENCE THE DETECTIVE STUDIES PATTERNS BEFORE MAKING CLAIMS


HTCYHQBUFPSKGQPGJSZYCSKTTRWMNJCDRNSQZMBFGVBYDASNOJKCGPRHJYXRPIRCZXGRZVNXTM

CHARGE OF THE LIGHT BRIGADE INTO THE VALLEY OF DEATH RODE THE SIX HUNDRED BRAVE CAVALIERS


67 83 84 17 44 25 23 41 37 20 56 66 82 83 20 44 83 16 64 13 17 75 72 37 41 23 25 28 44 32 67 20 33 17 56 66 60 63 34 15 88 83 70 23 67 20 25 72 71 18 37 27 28 26 77 81 41 66 82 63 70 59 26 77 22 37 56 83 44 89 66 18 84 17 68 25 37

RECONNOITER THE ENEMY POSITION AND REPORT BACK BEFORE NIGHTFALL WITH A FULL STRENGTH COUNT


01976 0363 02902 3822 0994 3812 04720 5985 1606 01272 2897 6049 00376 05123 04781 6048 6283 6614 5664 1655 4431 04779 6369 0315 06046 03845 04778 02204 0332 04466 6310 07301 04762 06025 5373 06671 00380 05653 01632 1018 2873 05037 2598 01636 5652 1665 4463 1020 5746 7923 05075 6306 6051 01339 2917 02261 05673 0352 05089 02599 6038 7227 2912 06344 02563 06286 07290 04791 05035 4791 3777 7886 0690 02843 06673 05997 0337 03823 5090 2573 00325 00707 01595 06319 5966

FAIL CLOSED IS A POSTURE NOT A SLOGAN TWO SQUARE CIPHER ENCRYPTS DIGRAPHS WITH TWO POLYBIUS ALPHABETS

Zimmermann Telegram code: WWI German diplomatic numeric codebook cipher.