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Let's say you generate an SSH RSA key pair with ssh-keygen -t rsa -b 2048. You'll end up with a public and private key.
id_rsa
id_rsa.pub
ssh-keygen will prompt: Enter passphrase (empty for no passphrase):
My understanding is that id_rsa will get one prime and id_rsa.pub will get another prime. What purpose does the ... |
I'm trying to solve the following question:
The following is an interactive proof for knowledge of the factorization of $n=pq$ ($p,q$ are two large primes), where $P$ doesn't wish to reveal the factorization itself ($p,q$). Determine whether it is a ZK proof. If it is, prove whether it is
perfect zero-knowledge or com... |
I'm given three values $s_0,s_1,s_2 \in \mathbb{Z}_m$ that follows the recursion formular $s_{n+1} = as_n+b \mod m$.
I know $m$ and want to calculate $a,b$. It's easy to see that $a=\frac{s_1-s_2}{s_0-s_1}$ however in my case $gcd(s_0-s_1,m)\neq 1$ thus I'm unable calculate the multiplicative inverse of $s_0-s_1 \mod m... |
How can I check if the random number generator library that I am using for my app is cryptographically secure or not?
|
In the process of finding RSA key pairs, we first find a e that is relatively prime to φ(n) (where n = p × q), and then find d such that e × d mod φ(n) = 1. Is d also relatively prime to φ(n), or not necessarily?
In practice, e is usually chosen to be 3 or 65537, but if we choose e to be a large enough number, can e an... |
Let $F(x_1,…,x_n)\mapsto(y_1,…,y_n)$ be some arbitrary computable function.
Suppose there are $n$ parties, where each party $i$ encrypt its message $m_i$ with a public key $\mathrm{pk}_i$ and obtain $c_i$. Is it possible for parties to execute a secure multi party computation $A$ with the same functionality as $F$, suc... |
Client-Server Example
apps/openssl req -x509 -new -newkey ec:<(apps/openssl ecparam -name secp384r1) -keyout ecdsa_CA.key -out ecdsa_CA.crt -nodes -subj "/CN=oqstest" -days 365 -config apps/openssl.cnf
apps/openssl req -new -newkey falcon512 -keyout falcon512_srv.key -out falcon512_srv.csr -nodes -subj "/CN=oqstest ser... |
Is there any educated views or references on how the PQC NIST finalists compare to legacy crypto with regards to power consumption?
Many thanks
|
I am searching literature on a more general notion of pseudorandom function where the range of the function is not the entire set of all binary strings of a given length, but rather a specified range dependent on the security parameter. Something like this, which I wrote up:
It seems that in some use cases, such a def... |
I'm aware of the many questions on this topic, but I'm still not sure what went wrong with my reasoning here below.
I'm assuming use of AES with key size $2^{256}$ and messages of size $2^{128}$, using ECB.
When I tried computing the expected number of plaintext-ciphertext pairs required until key-identification, I rea... |
I'm thinking of the problem of a distributed tinder: a network of peers, who want to match with each other confidentially.
The solution I'm thinking about is something along the lines of Alice sending some message encrypted with Bob's public key that implies she likes him. She will not send this message to Bob obvious... |
In this post, there's a discussion on single DES not having a key that yields the identity function. It mentions at the top:
That proposition is false for 2DES (EE), even restricted to one key, because twice applying encryption with the all-zero key (and the Final Swap built into the Final Permutation) yields identity... |
In this survey, I don't understand the necessary of coefficient (paragraph 4.1.2) growth and the choice of $X^d\pm 1 $ or $ X^d \pm X^{d/2} +1 $, since later introduces $q$ which doesn't mention the coefficient growth. I want to understand this paragraph please and its importance.
Thanks in advance
|
I am trying to make a e-voting system based on blockchain and I am trying to think about a way that i can verify that a vote is legal without reavling the identity of the voter.
One of the solutions we thougth about was to use linkable ring signatures, but the problem with this aproch is that the more keys we generate ... |
Say one encrypts multiple plain text blocks with same IV but different keys using AES-256-CBC, can one infer concatenated ciphertext block boundaries through digital forensics?
Example
Plain text block 1: foo
Plain text block 2: bar
Ciphertext block 1: <Buffer 88 65 7f 9f 7b 9d 47 51 21 cc 22 c0 2a 9e 69 57>
Ciphertext... |
The overall DP under the strong composition theorem for k-mechanisms is ($\epsilon \sqrt{k log(1/\delta)}$, k$\delta$) such that each individual mechanism has ($\epsilon, \delta$)-DP.
But what if say, 25% of the total k-mechanisms have $(\epsilon_1, \delta_1)$-DP, while the remaining 75% mechanisms have $(\epsilon_2, \... |
Paolo, in Algebra: chapter 0, defines a left-$R$-module as a ring, $R$, an abelian group, $M$, and a map $(R \times M \rightarrow M)$ such that:
$r(m+n) = rm+rn$
$(r+s)m = rm+sm$
$(rs)m = r(sm)$
$1m = m$
where $m,n\in M$ and $r,s\in R$
In the definition of RSA in Katz/Lindell's Intro to Modern Crypto, key generation re... |
Not sure about this question. Have thought about it, but not entirely sure whether the structure HAS to be reversible or not.
|
For https://asecuritysite.com/public/lwe_ring.pdf#page=9 , could anyone explain how the encryption and decryption for LWE work ?
When I do more reading on https://summerschool-croatia.cs.ru.nl/2015/Lattice-based%20crypto.pdf#page=29 , someone told me that when decrypting we get $q/2 M + r e$. If we can bound $r e$ by $... |
Due to a comment stating "... QR-PKE is secure (CPA)..." I've been thinking of how to prove that it's not CCA secure, and would like to understand whether my proof is correct.
Here's the QR-PKE scheme:
$KeyGen(1^n)$ produces:
$sk = (p,q)$ - two large n-bit primes
$pk = (n, x)$ where $N=pq$ and $x$ is a random $QNR \in... |
I'm trying to use HKDF-Expand to derive lots of keying material (> 64GB) from a pseudo-random 512 bit key.
Now according to the HKDF RFC, the maximum amount of keying material you can derive in a single call to HKDF-Expand is 255 * HashLength, which in my case would be 255 * 64 = 16,320 bytes of output (Since I'm usin... |
The question is somewhat complex and directed to clearing things out.
Suppose that $n$ is the order of the cyclic group. It $n - 1$ is the number of all private keys possible
n = 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
We also know that every private and public key has its modular inverse. T... |
I've learnt in the university course that using BLS, one can generate an aggregate signature using public keys of a given parties. We can then use a given party's public key to verify his participation in the aggregated signature.
But... does BLS or any other scheme allow us to encrypt a message with the aggregated sig... |
Suppose there are $n$ parties with public keys $pk_1,...,pk_n$.
Is it possible that a server S constructs an algorithm $A$ so that for some public random nonce $r$ given as input, S computes some "oblivious function" whose output is a tuple of several cipher texts of messages, without knowing the messages?
Namely S com... |
In MPC schemes like ABY or MOTION, the modulo operation is based on a ring $Z_{2^l}$. So for arithmetic sharing, it is relatively easy to make addition operation in the ring.
My question is, what if I want to do addition in a modulo different from $Z_{2^l}$. Say I want to compute $a+b\ mod\ p$, should I find a corresp... |
My understanding of zk SNARK is as follows: through (flattening -> R1CS -> QAP), bind the answer of the original proposition to the solution vector s of QAP, and then because QAP is an NP problem. So if the verification is passed, the verifier can be sure that the prover knows s.
And because of the NP problem, the only... |
I have what I believe to be a Vigenere or similar polyalphabetic cipher (IC = 0.0459). However, the ciphertext is further encoded by 'Latin-like' letters, meaning I don't have the ciphertext alphabet (but have some idea of the plaintext translations. For example, the words for 'Water' and 'Ice' (using Japanese 'Mizu' a... |
Are there any available formulas to determine a $Y$ coordinate given only an $X$ for the Ed25519 curve? The closest thing I've come to find is the recover_x(y, sign) function in the EdDSA RFC at https://www.rfc-editor.org/rfc/rfc8032.html#section-6
Edit:
Using @kelalaka 's steps, I implemented this python code, but it... |
I encountered notes stating that, for certain fixed $A$, such as $A \in M_{n\log(q)\times n}$ as follows:
\begin{bmatrix}
1 & 0 & 0 &\dots\\
2 & 0 & 0 &\dots\\
4 & 0 & 0 &\dots\\
&\dots\\
2^{\log(q)-1} & 0 & 0 &\dots \\
0 & 1 & 0 &\dots\\
0 & 2 & 0 &\dots\\
0 & 4 & 0 &\dots\\
&\dots\\
0 & 2^{\log(q)-1} & 0 &\dots\\
&\d... |
I've been thinking about ways to take advantage of multiple asymmetric encryption schemes so that each key could be a backup to the others in case of cryptanalysis of one given scheme.
Those public key schemes could each secure one share of a symmetric key splitting scheme (as answered in Is there a multiple asymmetric... |
I am trying to understand point addition in RFC8032 section 5.1.4, which references the paper "Twisted Edwards Curves Revisited" (https://eprint.iacr.org/2008/522.pdf) to describe the quick way they perform twisted Edwards curve addition with fewer inversions.
I am reading through the paper and it makes sense until I ... |
What kind of tests can be performed on a public key to check if it is likely a valid key? The tests should be relatively fast - i.e. not computationally intensive - and not include modular exponentiation.
I'm asking this question as developers generally work (or should work) on the principle of fail fast, in which an e... |
I read this paper on RSA cryptographic accumulators have some questions on a few points :
"Universal Accumulators with Efficient Nonmembership Proofs"
https://www.cs.purdue.edu/homes/ninghui/papers/accumulator_acns07.pdf
I noticed this from the paper :
"Note that computing witness using auxiliary information may not a... |
I want to debug bcrypt rounds with a static salt using this python lib
import bcrypt
salt = bcrypt.gensalt(14)
password = b"foo"
foo_1_round = bcrypt.kdf(password, salt, desired_key_bytes=10, rounds=1)
foo_2_rounds_manually = bcrypt.kdf(foo_1_round, salt, desired_key_bytes=10, rounds=1)
foo_2_rounds = bcrypt.kdf(passw... |
:-) Hello
I was wondering if the signature hash algorithm was a part of the private key or just the signing process?
Should a signature instance depend on the private key? (Of course, still talking about ECDSA)
If I don't sha256 my data before calling a signature instance SHA256withECDSA. Does this have the same eff... |
From a text on Interactive Proofs
$x \in {0,1}^n$ is input
$V$ is verifier
$P$ is prover
$r$ is $V$'s internal randomness
$P$ provides a value $y$ which is claimed to be equal to $f(x)$
(Completeness) For every $x \in {0,1}^n$
$Pr[out(V, x, r, P) = 1] \ge 1 - \delta_c$
(Soundness) For every $x \in {0,1}^n$ and every... |
I'm reading Matthew Green's blog post on ZK Interactive Proofs
I don't understand the part where he explains how using a time machine shows that the prover is leaking zero information
Specifically, assume that I (the Verifier) have some strategy that
‘extracts’ useful information about Google’s coloring after observin... |
Currently I'm working on an intercepting proxy server for mosh connections.
I'm able to intercept the ssh session to get the shared secret and alter the connection information for the mosh client. The mosh client is able to connect with my udp proxy server which is started for the requested mosh session and redirects t... |
i am currently searching for a post-quantum, asymmetric encryption since I need to keep a few files safe for the next decades.
AES 256 is what I am using currently, but I would like to leverage the additional safety of a asymmetric encryption (like encrypting something on a server I don't trust to 100% / storing the pr... |
I read about bactracking resistance:
http://cs.yale.edu/publications/techreports/tr1466.pdf
https://arxiv.org/pdf/1810.02227.pdf
https://www.schneier.com/wp-content/uploads/2017/10/paper-prngs.pdf
Story (Motivational Story) in first paper is interesting. But seems to be theoretical.
Backtracking resistance is critical... |
I am currently reading a book called Serious Cryptography written by Aumasson to learn about Security. There was a paragraph talking about the security goal named indistinguishability (attached below), which reads in the section "Security Goals":
I've informally defined the goal of security as "nothing can be
learned ... |
Let's consider PRNG which is updating its state by using some cryptographically secure hash function. So it takes some input, returns output and this output is a new input. And so on.
Of course there is a risk that such PRNG would fall into short cycle. But it can be resolved by combining the state with counter or Weyl... |
Has there been any use of cryptographic function as a kernel function with support vector machine? There are several standard kernels to be used with SVMs each with its own scenario.
I was not able to find any kernel function which is a cryptographic, one-way, or trapdoor function other than this example of using discr... |
My mathematical assumption is $(g^rx')^x = g^r$ where $x'$ is the multiplicative inverse of $x$ and $g$ is the generator of the group. I am calculating $(g^rx')^x$ in ModularArithmetic group G using Crypto++.
CryptoPP::Integer a, b, c, r(rng, 1, p);
a = G.Exponentiate(g, r);
b = G.Exponentiate(G.Exponentiate(g, G.Multi... |
Update: The question below was asked before I realized that this is being done to prevent a side channel attack: https://github.com/advisories/GHSA-5p8v-2xvp-pwmc
What I am still curious about, is the math behind why this solution still works to decrypt Elgamal ciphertext.
Original Question:
libgcrypt elgamal decryptio... |
Is it possible to commit to a value $s$ and then prove in NIZK way that $g = q^s$ ?
Both $g,q$ are known. Thank you.
|
I'd like to create a public/private RSA key pair where the OID of both keys is rsassaPss. I can create the private key fine but when I extract the public key I expected the OID to remain rsassaPss but it actually gets converted to rsaEncryption.
This SO post Why does OpenSSL differentiate between PSS and non-PSS for pr... |
What is IV predictable in the CBC mode?
We only need one IV once for CBC mode, does the IV-predictable means we know the initialization vector before we start a CBC mode? Or it means we know each string which is used to XOR with the plaintext, such as the first IV, c_i(the ith ciphertext)?
|
I'm a bit of a layman here and would be after a Python-based solution to this.
I would want a python-based application approach that is capable of generating data (e.g. csv file) that is locked immediately upon writing it, and it is not possible for the user to decrypt its contents on that end but rather a proxy indivi... |
I'm working with the dieharder package to test a PRNG, but I don't quite understand the ntup parameter.
I get that the ntuple should be a set of consecutive bits. But why is the ntup parameter for most tests set to 0? Is it because these tests don't need ntup to operate? What would exactly change if one would change th... |
I am currently studying zero knowledge proofs. (specifically A short tutorial of zero knowledge -- Oded Goldreich)
In the interactive proof system Definition it is required that the prover has unbounded computation capabilities (i.e. executes a computationally unbounded strategy) while the verifier has somehow bounded ... |
I need to cipher and decipher text with randomly access. For this I decided to use AES in CTR mode which is a good compromise between CBC and GCM.
But CTR mode is malleable. It is not a big problem because texts that I will cipher have not predefine patterns and I don’t need authentication, I just want to avoid the abi... |
What requirements KDF and randomness extractor does not have to meet, but the the hash function have to meet? I suspect that using hash functions as KDFs and randomness extractors is enough, but in some aspects more than we need.
If we consider some weak, biased source of entropy it looks like randomness extractor:
do... |
I'm developing a device where I need to store a symmetric key that the customer uploads to the device.
The device is offline at all times, so centralized storage in HSM is not an option.
The device does not have a key-pad.
The key is used for data encryption/decryption when the device is active.
The key cannot be store... |
In MPC, AND and XOR gates are two mostly used gates. However, most of the solutions (Garbled Circuit or Boolean Secret Sharing) considered these gates having 2 input wires and 1 output wire.
I am curious on how the case of multiple input wires can be handled. Specially, suppose there are 3 parties and they want to comp... |
Modern hash function have to be at least 256-bit, due to birthday attack. But let's consider 128-bit hash function which takes as an input:
plaintext $\oplus$ salt
Salt may be know to attacker. Do such a functions would be secure if it has no other flaws?
|
After reading this topic:
How do I construct a 256-bit hash function from 128-bit AES?
It looks like it can be done. If we have 128-bit into 128-bit secure mapping, indistinguishable from random (but vulnerable for birthday attack itself, because of its size), can we construct secure 256-bit hash function (especially i... |
From my limited research into this topic, it seems that AES can be brute-forced. One-time pad, on the other hand, cannot. Why then is it better to use AES than it is to use one-time pad? The only answer I have come to is performance, but this doesn't seem quite right.
|
Are the digital signatures used in cryptocurrencies such as Bitcoin a type of zero-knowledge proof?
|
I am trying to develop a Rest API using Kotlin/Spring Boot. The JSON request in it, should have a hashed password that was done using Argon2id. Getting the password hashed was pretty straight forward and simple enough! But I am stumped at how to verify what I receive in the JSON request is correct or not. That is match... |
I am currently working through the exercises in A Graduate Course in Applied Cryptography by Dan Boneh. I am stuck on exercise 4.16 (page 188 in this PDF)
In the GGM tree construction for constructing a PRF from a PRG, the secret key is used at the root of the tree and the input is used to trace a path through the tree... |
I was looking through https://csrc.nist.gov/projects/post-quantum-cryptography/selected-algorithms-2022
How can one begin to mathematically verify if there are no backdoors to these selected post quantum algorithms?
|
When I searched Google, the top result said
On average, processing for ECC is about four times less CPU-intensive than for RSA.
Yeah, but under what condition? The page says "A 256-bit EC certificate (the minimum length supported) is roughly equivalent to a 3k RSA cert. " Then, does the above 1/4 consumption mean a ... |
Presuming (if we ought to?) that we classify instantiations of algorithms as primitives,
https://cwe.mitre.org/data/definitions/1240.html
Colloquially, one would say that AES (and sometimes AES-256) is the "cryptographic
primitive," because it is the algorithm that realizes the concept of symmetric
encryption (without... |
I am already using the 2 they suggest :
https://github.com/usnistgov/SP800-90B_EntropyAssessment https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90B.pdf
but, here is where I run into issues, I have a a file with 1,000,000 bits, what's the right format for the input? they don't state that, should it be... |
Is it possible to derive private key directly from public key alone using a powerful Quantum computer.
|
I am currently learning about lattice-based cryptography and, reading from A Decade of Lattice Cryptography by Peikert, specifically section 2.3, it emerges that
[...] if the parameter s is greater or equal than the smoothing parameter of a lattice, then the sum of independent discrete gaussians (over that lattice) is ... |
I don’t know how to find.
Like this picture shows.
|
I'm wondering if a binary elliptic curve (such as sect571r1 aka B-571) supports pairs of asymmetric operations (for example, either sign/verify or encrypt/decrypt) on a fixed bit or byte input size in a way that this operation becomes fully bijective on those bytes/bits (where the inverse operation requires the opposit... |
Say that I have a signing/verification key pair $(sk,vk)$ and I generate a signature $\sigma$ over a message $m$. Then, I want to prove to someone else of this fact, which can be done in two different manners:
I directly send $(\sigma,m)$.
I compute a non-interactive zero knowledge argument $\pi$ for the statement: "I... |
Pseudorandom correlation generators (PCG) exist for tensor products, this is described in Figure 1 of [1]. Basically we want party 1 to hold $(x_0, z_0)$ and party 2 to hold $(x_1, z_1)$ such that $x_0 \otimes x_1 = z_0 + z_1$. Let $n = |x_0| = |x_1|$ so the length of $z_0, z_1$ is $n^2$.
My understanding is that PCG s... |
I am trying to understand the AESGcm encryption and decryption and there's one field associated data in Encryption and Decryption methods.
https://learn.microsoft.com/en-us/dotnet/api/system.security.cryptography.aesgcm.decrypt?view=net-7.0#system-security-cryptography-aesgcm-decrypt(system-byte()-system-byte()-system-... |
In Section 2.1 and Section 2.2 of the paper Strongly Unforgeable Signatures Based on Computational Diffie-Hellman" by Dan Boneh et. al.", I noticed the paragraphs quoted as
"We define the advantage of an adversary A in attacking the signature scheme as the probability that A wins the above game, taken over the random b... |
Time locks enables us to encrypt data for a period of time, up to a certain deadline, such that even a computationally powerful adversary is not able to learn any substantial information about the data before the deadline. Time locks received a lot of attention ever since blockchain smart contracts have started using t... |
My background is that of a reasonably experienced programmer who hasn't learnt Comp Science formally. I am now learning Cryptography as a hobby in my spare time & I think I have learnt a reasonable amount of stuff through self-study.
I have learnt Elementary Number, Abstract Algebra & some amount of Algebraic Geometry ... |
I am implementing the Advanced Encryption Standard from scratch, but I came up with a question that I was unable to answer.
Why does no one implement AES with other sizes?
I've searched about that, and some people say it is only because it is not in the standard (which is understandable), but other's says that it was n... |
A question about Schnorr group.
Am I right that this is basically a protection against discrete-log solvers?
So Schnorr signature is better than ElGamal in that sense?
|
I'm writing a higher-order function in Haskell for use in public-key algorithms; it works equally well for RSA or elliptic curves. I'd like to test it for susceptibility to side channel attacks. How should I do this? The software runs on an ordinary Linux or BSD box; I'm not thinking of hardware implementations.
The fu... |
I want to generate a seed using CSPRNG. I then want to shuffle a standard pack of playing cards (52) using said seed, however, I want the shuffle to be accurate enough that it covers all the possible shuffle outcomes which is 52 factorial. I read from a blog post online that I need at least 226 bits of entropy to cover... |
There are 64-bit universal or almost universal hash functions, like CLHASH or VHASH:
https://arxiv.org/pdf/1503.03465.pdf
https://eprint.iacr.org/2007/338.pdf
Can we create secure 256-bit hash function by concatenation of this hash functions (by using different key for every function)? Similarly like authors of ECHO ha... |
We consider a language that is $\{0,1\}^n$. We consider three variables $A$, $B$ and $K$ part of that language. A and K are generated through true random generator.
We consider not two as is traditional but three Turing machines:
-The encrypter. This takes as input a key $K$ and a value $A$. This output $B$ in polynomi... |
while reading Introduction to modern cryptography by Katz and Lindell, I came across these two experiments:
For me, they look like it's the same thing. Can you please explain me the difference? Thanks :)
|
The setup is the following:
Alice has a secret x
Alice can generate proofs P1, P2, P3, ...
Bob (an outsider) should be able to prove that any two proofs come from the same x
without communicating with Alice
Does such a proving protocol exist?
This feels like a problem belonging to the realms of non-interactive zero-k... |
I have a C++ application on Intel x86 using openssl to make a connection to a server. What is the fastest cipher that openssl supports? My implementation is currently using ECDHE-ECDSA-AES128-GCM-SHA256.
I know of the openssl speed command but the supported ciphers don't easily map to the cipher names given to openssl ... |
I looked through NIST's official test vectors (CAVP) for the AES-GCM mode, and noticed that there are some test vectors in there with 8-bit or 1024-bit IVs. But as far as I understand, the GCM guideline specifically insists on using 96-bit IVs.
I took a glance at the SP 800-38D and found no clear guidelines on using th... |
I am learning/exploring the openssl library for encrypting and decrypting data
while encryption goes through fine I see standalone decryption not working as I expected.
The test vector I am using is
# Key 2b7e151628aed2a6abf7158809cf4f3c
# IV 000102030405060708090a0b0c0d0e0f
# Block #1
# Plaintext 6bc1bee22e409f96e93d7... |
We want to perform a known plaintext attack on the enigma M3, the goal is to reach the initial settings of the 3 rotors. I tried to bruteforce those values since I know the plaintext, ciphertext, positions of the rotors and the reflector setting, but I couldn't find the initial position of the 3 rotors.
Is there any me... |
I am trying to understand how the forgery attack works when using the CBC-MAC Algorithm
|
This is about the same random ladder algorithm as my previous question. It computes f(g,n,r)=n*g or g^n (depending on the group notation), where g is a generator of a group. Suppose n=5882353. This can be calculated as
((((((((((1*2*2+1)*2+1)*2*2*2+1)*2+1)*2+1)*2*2*2*2*2*2+1)*2+1)*2+1)*2+1)*2+1)*2*2*2*2+1
(((((((1*3*3+... |
I'm a beginner in the cryptography domain. Can anyone help me understand Additive Secret Sharing and Linear Secret Sharing? Are there any sources or references to understand their difference and how they work?
|
I am trying to understand how XOR operation can lead us to know the plaintext if we can predict the iv using the chosen plaintext attack game.
|
I want to store passwords in a database in a way I can reuse them to authenticate users (symmetrical encryption).
I read some good information here: https://cheatsheetseries.owasp.org/cheatsheets/Cryptographic_Storage_Cheat_Sheet.html#cryptographic-storage-cheat-sheet
After reading, here is what I (think I) need:
Symm... |
As per my understanding AES introduces diffusion in each block it encrypts even with ECB as mode of operation. If that is the case how the patterns are retained in each block?
In this blog https://words.filippo.io/the-ecb-penguin/ penguin outline, eye, body, legs are retained. I expected distorted parts of penguin.
|
Assume we have an $n$-dimensional real-valued function $f$ whose $\ell_1$ sensitivity is equal to $GS(f) = 1$. We can also assume the sensitivity of each dimension is also $\Delta f = 1$.
For pure differential privacy, we have the Laplace Mechanism, whose magnitude is parametrized by the privacy level $\epsilon > 0$ an... |
Something like:
$$ h = Hash(\texttt{"Some String"} \mathbin\| h)$$
|
I've looked at this crypto SE post but it doesn't address the how of my question.
I've been interested in cryptography for some time. I wrote a relatively basic cryptosystem in Python that uses base conversion as one of its layers of security (I don't actually use it for anything, don't worry). I've heard time and tim... |
I’m just seeking a better understanding as to the logic behind design of the A5/1 cipher’s keystream generator. Why are the registers degree chosen in such a fashion (19,22 and 23 bits long respectively)? I have heard because they are co-prime but have little understanding how this may influence the system.
The reason ... |
in learning with error encryption scheme (e.g. in Kyber scheme).
there are two vectors:
$u = r^t A + e_2$ and $v= r^t * pk + e_3 + \lfloor \frac{q}{2}\rceil m$
such that $pk = As +e_1$.
my question is does the encryption still secure if we omit $e_3$ so $v = r^t * pk + \lfloor \frac{q}{2}\rceil m $.
as far as I kn... |
Is there a way to determine the private key (or the phi value) without n factorisation if one knows the ciphertext and the public key and that each letter of the (English) alphabet has been encrypted individually?
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The Fiat-Shamir transform typically works by substituting (public) coin tosses from the verifier by hashes of the prover's messages until this point, i.e.: $$H(x,\alpha_1) = \beta_1, \\ H(x,\alpha_1, \alpha_2) = \beta_2,\\H(x,\alpha_1, \alpha_2, \alpha_3) = \beta_3,\\\vdots$$ where $x$ is the public input of the protoc... |
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