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The wikipedia page on computational indistinguishability says that two ensembles are not distinguishable if "any non-uniform probabilistic polynomial time algorithm A" cannot tell them apart. To help me better understand the definition, I searched for an example of an algorithm that did not fit the above restriction---... |
First of all, the Guillou-Quisquater digital signature scheme is:
Note everything is $\bmod n$. Message is denoted by $m$.
Private key: $s$
Public key: Hash function $H$, $e$, $L=s^e\bmod n$
To sign: Alice chooses random $r$. Computes $c=H(m||x)$ with $x=r^e\bmod n$; $y=r\cdot s^c\bmod n$; send Bob $x$ and $y$.
To ve... |
I've had many questions on Stackoverflow on how to minimize the output of a cipher - during encryption of course - to the same size as the input. Obviously this is possible for a single block of plaintext, but it gets harder when the plaintext size is larger than one block. Using a stream cipher is possible, but you wo... |
In the last week, the discrete logarithm problem was broken for the binary fields $\mathbb{F}_{2^{(14 \times 127)}}$ and $\mathbb{F}_{2^{(27 \times 73)}}$.
Pairing-based cryptography using binary fields currently relies on fields such as $\mathbb{F}_{2^{4\times353}}$ (80-bit level of security) and $\mathbb{F}_{2^{4\tim... |
The TLS protocol includes an optional Server Key Exchange message that is signed by the server. It seems to me that this message is digitally signed only to prove to the client that the message originated from the server.
The general purpose of a Digital Signature is to provide a proof of origin that can be verified b... |
What is the most used Algorithm/Technique in Steganography? I made some research about the algorithm/technique and I think Least Significat Bit(LSB) is the most used algorithm, is there any more efficient algorithm/technique that can be use for Steganography aside from LSB?
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One of the simplest possible cipher modes is setting each successive key as a function F of the previous one.
K[0] = Master key
C[i] = E(K[i],P[i]), K[i]=F(K[i-1])
This is similar to the counter mode CTR, but the key is incremented instead of the plaintext.
Obviously this mode is slower than the others, since key sche... |
I'm having some fun designing a key stretching algorithm that can be implemented in pure Python. It's built entirely out of the standard library's hash functions in an attempt to at least wrest some speed out of this particular language.
I came up with the following construct for mutating memory. Given a hasher initial... |
Suppose the attacker knows $X, Z$ such that
$H(X || Y) = Z$
If bit-length(Y) < 60 then a brute force attack is possible.
What if bit-length(Z) = 256 (such as in SHA-256), bit-length(X) = 128, or bit-length(Y) = 256? Are there any published paper with results/experiments with SHA-256/512 in full or reduced rounds? Are ... |
First I apologize if this question is better tailored for SO, but since I'm using the method for crypto stuff, I thought I'd ask anybody that might know here. Karatsuba algorithm does a pretty good job, but maybe there is something that works better.
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Keccak, the construction selected for SHA-3 is very interesting. It seems unlike other primitives and has chosen very simple constants. (Keccak talk PDF)
The initial values of the state in Keccak is all zero, why?
The round constants have just a few bits set, why is this?
Previous primitives like SHA-2, use pseudorando... |
I've been tasked with building up some security exercises (basic CTF training kind of stuff) for work. This should contain a bit of crypto, but my knowledge in this space has been limited to using the right tools, not trying to roll my own, etc, so coming up with an example of bad crypto, but believably real, has been ... |
I am trying to do a homework in which implement a variation of this paper and I don't know how to generate a polynomial of degree $m-1$. This polynomial is used to generate the $y_0$ and $y_1$ values.
I am using JCE for doing the coding. What do I need to do to achieve this?
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Use the notations form the Wikipedia article Paillier Cryptosystem
, assume that the chipertext $c$ and $c^{\lambda} \mod n^2$ are both given, is it possible to compute $\lambda$ easily?
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I'm encrypting a file with AES-256 in CBC mode. I needed to add an HMAC for authentication and validation of the file contents and passphrase, so I used a SHA-256 HMAC over chunks of my file cumulatively.
My main question is how to derive both an HMAC key and my AES key from an input passphrase. I'm currently taking t... |
Comparing to this question, assume $C, M \in \mathbb Z^*_{n^2}$, $e \ge 3$, is it hard to compute $M$ that satisfies $C=M^e \mod n^2$ when $C$ and $(n, e)$ are given?
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Is there any complexity analysis between Karatsuba and Montgomery multiplication algorithms? It seems that Karatsuba is more general in the sense that is not modulo tuned while Montgomery it is. Does a also a hybrid model using Karasuba and Montogomery exists?
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Modern stream ciphers usually predicts the usage of a nonce (also termed as IV) in the cryptosystem. The cost of initializing the cipher with the nonce varies from algorithm to algorithm (for instance, this cost seems very high on HC-256 and negligible on Salsa 20). I would like to know the correct usage pattern of a n... |
In projective coordinates point-at-infinity can be identified with z=0. How to identify the point-at-infinity in affine coordinate.
Whether x=0 and y=0 can be considered as point-at-infinity in affine coordinate?
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Assuming the ability to launch Chosen Plaintext Attacks (CPA), how many oracle calls does an attacker need to break the affine cipher? How does it work?
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In the Paillier cryptosystem [1] the encryption of $m \in \mathbb{Z}_N$ with randomness $r \in \mathbb{Z}_n^*$ is $c = g^m r^n \bmod{n^2}$.
A proof of correct encryption could look like presented in section 4.2 of [2]:
"Suppose a prover $P$ presents a sceptical verifier $V$ with a ciphertext $c$ and claims that it enc... |
This is theoretical question. I'd like to know if it's possible (and what are eventually the consequences), not that I'm going to do it in one of my projects. ;)
The first hashing functions created were based on a symmetric cipher (just like the first Unix crypt was based on DES). The idea was simple. Use the password ... |
I'm aware that it's crucial to include the IV when calculating the HMAC of a ciphertext (assuming an IV is used). Can anyone explain, in simple terms, why this is?
Furthermore, assume that there is other metadata associated with the cipher, which needs to be known to correctly decrypt the ciphertext (for example, the ... |
I need to transmit long encrypted messages to a smartcard over a limited capacity link so I need to fragment the messages somewhere before sending thzm.
My problem is that I split the message into 64-byte blocks and then apply a pkcs7 padding. The result is that the padded message always ends with a full block of 16s b... |
I am looking for a way to generate an "insecure" public key pair. and by insecure I actually mean a pair that is breakable using brute-force (or other encryption) methods.
As far as I know PGP started with 128bit-keys. and at this point I can only find tools to generate keys using 1024bit or more.
Is there a way to gen... |
Is TrueCrypt use of cascading encryption safe? Is it useful? TrueCrypt is arguably one of the most popular and widely used encryption applications in use today, yet it seems to use a very unconventional scheme.
The software offers cascading encryption, where the user can specify either double or triple encryption u... |
The professor left us a question on ElGamal signatures:
Given the hash function $H$ and message $M$, choose a random $r$ and compute $h=g^r$ and $H(M||h)$. Show that, if $H(M)$ is used instead of $H(M||h)$, the signature can be existentially forged.
I am struggling with the problem, and I think that maybe we can get ... |
I want to find two strings containing special words like "yes" or "no", mixed with random characters, for which the MD5 hash is equal.
An example of what I'm looking for:
First string : YES/d6g45d78h74jfhcf MD5 : 4cf349066ce85e0c947eb1d0c94c13b1
Next string : NO/djf986f98edf8dfv4 MD5 : 7fdefd9bd8a46db9b48a323e... |
On a recent question it became apparent that there's a significant difference between an HMAC of input data and a hash of input data.
What exactly is the difference between an HMAC and a hash of a span of input data?
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A homomorphic hash function is a function $H : A \to B$ between two sets with some algebraic structure $(A, *)$ and $(B, \star)$ such that
$H$ is collision resistant, i.e. it is hard to find $x \neq y$ such that $H(x) = H(y)$ and
$H$ is a homomorphism, i.e. $H(x * y) = H(x) \star H(y)$.
Are there any practical realiz... |
As the topic says, since when can ECC cryptography be freely used?
Is it not widely used because of patents? There is no alternative to it on embedded devices and smart cards.
Just to mention: I am not from the USA. I'm a simple user who wants ECC to be wide supported.
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Usually, in cryptography, one is interested in debiasing a stream of independent (true) random bits, and several algorithms exist to do this. What about the converse? Let's assume I have a stream of independent and unbiased random bits at my disposal, and that I would like to generate a stream of statistically independ... |
It is conjectured that SHA-1 has been broken from the "research" perspective, but not in the real world; that is, there exists an algebraic attack that explores weaknesses on its algebraic construction. The same happens for MD5, but MD5 has been practically broken by finding collisions in the real world. Can we still u... |
I think I understand why RSA is hard to attack but I'd like to get clarification if I actually do.
Assume there are two people, Alice and Bob, who are attempting to communicate privately but that we can listen to all of their messages to each other. Assume we know they're attempting to communicate using RSA and that A... |
I want to generate a random elliptic curve over a prime field. What are the conditions I should satisfy?
For the NIST recommended standard ECC-224 bit curve with prime $p=2^{224}-2^{96}+1$, a reduction technique is given by $(z_1+z_2+z_3-z_4-z_5)
\bmod{p}$, what is the logic behind in this?
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If I sign the word HELLO with the mechanism "NONEwithRSA" with the same private key, will I always have the same signature?
A Java example always return different byte array :
PKCS11Provider provider = new PKCS11Provider(this);
List<PKCS11Slot> slots = PKCS11Slot.enumerateSlots(provider);
PKCS11Session session = null;
... |
Is SHA-1 collision free on data up to 20 bytes long (lenght of hash / internal state)? That means that every input produce unique output, but you surely know that, i just write it in order my question to be accepted by the site :)
If yes - which other hash functions does it apply to and what is the corresponding maxima... |
Is there an efficient way (algorihtm) to compute the solutions of the congruence $x^n\equiv a \pmod p$?
$n\in \mathbb{N}$
$a\in\mathbb{Z}_p$
$p$ is a large prime number
Note that:
By efficient I mean computationally efficient even when the given prime $p$ is appropriate for use in cryptographic protocols (hard to fi... |
I'm sure it can, because SRP (secure remote protocol) can be implemented everywhere where Diffie-Hellman works, but I need a proof to put this aspect into Wikipedia.
Edit: ok, can it be at least partially moved to elliptic curves?
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In reference to this question, what are the "stronger security properties" that HMAC provides over MAC. I got that MAC requires an IV whereas HMAC doesn't. I also understood that MAC may reveal information about plaintext in contrast to HMAC. Is my understanding right?
What are other security properties of MAC and HMAC... |
I'm currently working on Ciphertext Policy Attribute-Based Encryption (CP-ABE). So far I'm only using it with a basic understanding how it actually works. Now I want to understand it a bit better, but I've never learned anything about bilinear groups or pairing-based cryptography.
To start with I would like to calculat... |
I know I'm treading in dangerous waters asking this - my comprehension of cryptography math is sorely lacking. On the flip side it gives me massive admiration for what many of you are able to do.
From my understanding of crypto functions, a password is typically used to create a xxx-bit secret key. This could be 128-b... |
When nowadays I point my browser to https sites, the cipher that is on most occasions used is Camellia. My browsers (Chrome and Firefox) seem to prefer it, even when AES is available.
Is that not kind of dangerous? Camellia did not receive so much scrutiny as did e.g. AES, so we know actually less about its security. W... |
I have 320 bits of seed data (actually 512 bits of data with 320 bits of entropy, derived from a Diffie-Hellman shared secret and nonces). The PRNG I am using at the moment is the android version of SHA1PRNG. As far as I can tell, it has 160 bits of internal state, and so any entropy over 160 bits would be wasted. Coul... |
I am implementing the encryption layer for a communication protocol. The bulk encryption method used is either AES-CCM or AES-GCM. Due to implementation details, encryption of packets is usually, but not necessarily, performed by the sender in the same order the packets are sent over the network. This means two things:... |
Assume that we have an already assigned Multiplicative Cyclic Group $\mathbb Z_p^*$ with order $q=p-1$, and $p$ is a prime number, is it possible to create a bilinear function $\hat{e}: \mathbb Z_p^* \times \mathbb Z_p^* \rightarrow \mathbb G_2$ with the property that follows:
$$\hat{e}(g^{a},g^{sb})=\hat{e}(g^{b},g^{s... |
I've been tasked with reverse engineering an unknown crypto function. The function uses the following constants:
$a=380951$:
I noticed that this is a prime number
$b=3182$:
I noted that this is a prime number + 1
The math function applied is as follows:
$\mathrm{result}=((\mathrm{value} \bmod a) \cdot b) \bmod a$
Th... |
It is known that computing $a^x \bmod N$ takes $O(|x| + \mathrm{pop}(x))$ multiplications modulo $N$, where $|x|$ is the number of bits of $x$ and $\mathrm{pop}(x)$ is the number of $1$ bits (Hamming weight). This suggests a side channel attack by measuring the run time of the exponentiation.
Can the number of $1$ bit... |
ChaCha8 takes a 8 byte nonce (or IV) that should not be the same twice for the same key. Generating this nonce randomly makes me very very nervous for collisions.
Is it safe to generate this nonce deterministically?
For example the first 6 bytes could be the number of milliseconds since the Unix epoch, with the last 2 ... |
Assume that we have a linear equation like this:
$$ax=b \pmod n$$
when $x$ is the unknown, and $a$ is not an invertible element in $n$.
is finding $x$ a hard problem?
(by solving I mean finding an $x$ that satisfies the equation)
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See this question. The comment by Brett Hale stated:
On the other hand, ensuring $(p - 1)$ has a large prime factor requires very little extra effort.
What's actually the 'little extra effort'?
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The RFC states the following:
3.2. The 'info' Input to HKDF
While the 'info' value is optional in the definition of HKDF, it is often of great importance in applications. Its main objective is to bind the derived key material to application- and context-specific information. For example, 'info' may contain a protoc... |
I am looking into implementing Pohlig-Hellman exponentiation cipher and I would like to know how secure that algorithm is? I am guessing it's security relates greatly to the prime number used in it. Does anyone have some reference that might be helpful in determining the minimal prime number one should use in order to ... |
As I understand from this article about homomorphic encryption, it
mainly aims to enhance the security of cloud computing. We should be able to encrypt data and send it to the cloud. After it is send, we should be able to make computation on the encrypted data and the result of this computation is an encrypted data too... |
I am trying to understand why is bcrypt called a Key Derivation Function?
I looked up the details of Ekfblowfish on Usenix article.
After reading it, I understood that:
The password is the encryption key. The length of the password can vary and so the length of the encryption key can vary (max is 56 bytes or 448 bits)... |
I would like to ask you about your opinion on the following scheme of combining a master key and a nonce and stretching the result to the full 256-bytes RC4 key.
Master key $K_m$ is a pre-shared secret of length $M$ bytes
nonce $K_n$ is sent unencrypted and is of length $N$ bytes
both $K_m$ and $K_n$ are chosen to be ... |
This answer lists two commutative cipher algorithms - Pohlig-Hellman and SRA. However, they don't appear to be too secure.
My question is, here there any commutative ciphers out there that are secure enough for sensitive data encryption / decryption (money is involved) and at the same time not burdening enough on the c... |
I would like to implement a mental poker protocol in a secure fashion. How should I go about that without (preferably) infringing on the Mental Poker Framework patent?
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Good day to everyone.
I am trying to implement an e voting system (just for reference -it is not important though-it is described at the Internet Voting Protocol Based on Improved Implicit Security by Abhishek Parakh & Subhash Kak Version of record first published: 29 Jun 2010. ).
The protocol I am trying to implement... |
In the Paillier cryptosystem [1] the encryption of $m \in \mathbb{Z}_N$ with randomness $r \in \mathbb{Z}_n^*$ is $c = g^m r^n \bmod{n^2}$.
The additive-homomorphic property of the system shows that
$g^{m_1} r_1^n \cdot g^{m_2} r_2^n = g^{m_1+m_2} (r_1r_2)^n = g^{m_1+m_2} r'^n\mod n^2 = m_1 + m_2 \mod n$
so the result... |
I have to license a java application and want to code a quick implementation, the scheme I came up with is:
The Application calculates a string X which we assume to be the md5 sum of the computer's mac address, the current date and some other information.
the application returns a string Y equal to the last 16 digits ... |
What is the main difference of the three?
Can I use only one of them for everything (e.g. GPG for SSH authentication)
If I encrypt my private key with a pass-phrase, is it strong enough so that if someone steals my laptop or private key, I'm safe?
If not, what about encrypting my private key with the scrypt algorithm?
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Below is my implementation of the RSA algorithm. Actually I'm choosing the private key (d) instead of public key (e) and computing the public key.It is working fine but
I want to know if this is a safe implementation? and also Is any part in the code could lead to factorization of the modulus (n), thereby breaking the ... |
I plan to build my own crypto library. The project will be primarily for me to learn (and if useful for no other purpose, that is fine). In the past I have implemented a few hashes, and AES quite a few times while learning about it, but those projects were solely for me to learn, not for any field use. With this one I'... |
What data is saved in RSA private key in openssl? How to view it?
Wikpedia says these variables are saved.
|
I have a homework problem:
Explain how to find $m_{0}$ and $c$ such that $P[c=c': k \leftarrow K, c' \leftarrow E(k, m_{0})] > 0$
where P is probability and k is chosen uniformly.
I do not know if I understand the question correctly. The notation should imply that what is the probability of the condition $c=c'$ given a... |
I've played a lot with VIC and enjoy its complexity and effectiveness as a field cipher. However, RC4 has caught my attention lately and I've read there is a RC4-52 variant that can be done by hand.
Can anybody describe the rc4-52 algorithm? Is it with a deck of cards and just a swap of the values, or must they still b... |
I have been doing a project that uses the PBC library developed by Ben Lynn. But I am still not clear on how PBC is related to ECC.
I know that this is a site for complex crypto QA, but I did not know where else my question would be answered. I have tried to learn from online sites, but I don't understand most of them.... |
Should the secret message of Shamir's secret-sharing algorithm be interpreted and processed byte by byte?
Interpreting it byte by byte makes it easier to process, but in case one of the shareholders decides to tamper with some of the bytes in his possession, this will affect the secret reconstruction.
This is a seriou... |
I'm being asked to use an encryption algorithm in my code, and besides the fact that I'm sure there will be implementation faults that lead to vulnerabilities, I also have concerns about the algorithm itself. I'd like to know how strongly I need to convince these guys to not use this. If it is an acceptable algorithm a... |
I need to compute a function $h^l$, where h is an element of G2 and l is a rational number. How can this be done using the PBC library?
I have converted the h to an element in G2
As far as I have seen, for exponentiation, PBC has two functions :
element_pow_zn, and
element_pow_mpz
The first function is used when both ... |
DJB described curve25519 in his paper which can be found here (PDF). It seems that the main purpose was for Diffie-Hellman key exchange. I think this means that Discrete Log is supposed to be hard on curve25519.
My questions is whether DDH (Decisional Diffie-Hellman) assumption is conjectured to hold on curve25519 too ... |
I'm exploring ways of encrypting Intel hex files we send to customers for flashing onto an embedded device. The embedded processor itself has a built-in mechanism that prevents anyone from reading the contents of the flash memory unless you unlock it using a 128-bit password.
A trivial method I thought of to encrypt th... |
The Poly1305-AES paper summarizes the MAC as
$$ \mathrm{Poly1305}(m, \mathrm{AES}_k(n)) = {H_r(m) + \mathrm{AES}_k(n)} \mod 2^{128} $$
Can I presume that $+$ here is just meant as a form of 16-byte mixing $H_r(m)$ and $\mathrm{AES}_k(n)$, and that XOR would be equally effective (since both already are 16 bytes)?
Now f... |
I would like a multiparty protocol, secure in the honest-but-curious model at least, but hopefully other situations as well, that can do the following: every party among $\{P_1, P_2, \ldots P_n\}$ puts in a value $v_i$, and the set of $v_i$'s is computed, in such a way that no one knows which party contributed which $v... |
Assume Alice and Bob are using RSA to create a common session key and Cindy is listening, attempting to obtain the session key.
Alice and Bob each have their public- and private-key pairs ($\left[pub_{A}, pri_{A}\right]$ for Alice and $\left[pub_{B}, pri_{B}\right]$ for Bob) and Alice, Bob, and Cindy all know everyone ... |
PKCS#1 is one of the most used (de-facto) standard for real-world use of RSA.
That's for good reasons: PKCS#1 is well thought, versatile, understandable, has been relatively stable for over two decades, and remains practically secure in its original form, contrary to some other standardized uses¹ of RSA. The major upgr... |
I want to divide a system that maintains these properties, based on Shamir's Secret Sharing:
A secret key is split up to N pieces, where T of them are enough to reconstruct the key.
The original key is then destroyed and doesn't exist anywhere except the N separate pieces.
The information unlocked by the T signatures ... |
I am just curious. We have a group $G$ and its subgroup $H$ with a generator element $h \in H$. How difficult is it to check for $x \in G$ that $x \in \langle h \rangle$? Is there a better way than testing $x \equiv h^1,\ x \equiv h^2,\ x \equiv h^3,\ ...$?
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I have an RSA group with modulus $n = p \cdot q$, two safe primes $p=2p'+1$ and $q=2q'+1$ and the "public" and "private" key exponents $d$ and $e$. $\phi(n) = 4p'q'$ is the order of the RSA group. If I know $\phi(n)$ I can calculate $p$ and $q$. I ask myself what is if I know $e$ and $d$ (and $m$ and $n$) with $m^{d \c... |
I am wondering: what is the most common, or most used, block cipher mode used that goes with CTS (CypherText Stealing)?
Is it ebc or cbc?
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I'm trying to understand Feldman's VSS Scheme. The basic idea of that scheme is that one uses Shamir secret sharing to share a secret and commitments of the coefficients of the polynomial to allow the other party to verify that the share they received is valid. I implemented it in code following the wikipedia page, but... |
In a paper it says: "To convince a verifier that a group element is a quadratic residue, the prover executes the following proof with the verifier":
$PK \left\{ (\alpha) : y = \pm g^\alpha \right\}$
Does someone know how such proof is implemented by a signature proof of knowledge? The group is an RSA group $\mathrm{G} ... |
Bob know's Alice's public key, and he wants to make sure he's connecting to the one which has that key. Furthermore, Alice wants to verify when she gets a connection from Bob who'll give his public key that he is indeed the one who has that key.
Bob will send Alice half the AES private key and half the initialization v... |
Suppose that $p$ is a safe prime of 2048 bits ($p = 2q + 1$, and $q$ is prime).
Suppose that one is given two pairs $(x_1, y_1)$ and $(x_2, y_2)$ such that:
$y_1 = x_1^{r_1} \pmod p$
$y_2 = x_2^{r_2} \pmod p$
Where $r_1$ and $r_2$ are unknowns.
Is it easy or hard to check if $r_1 = r_2$ without further knowledge? Does ... |
I am currently doing some research on universally verifiable mixnets, but it seems to me that there are too few papers about them after 2006 or so and most of them come from the team of Douglas Winkstrom.
Is this correct?
Can anybody point me to current references about mixnets and their use in voting protocols?
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I want to create a simple secured connection protocol over TCP/IP.
I just want to connect from my mobile device to a server securely.
Firstly I thought to use an SSL connection, but I changed my mind and decided to create my own protocol.
I am thinking about key exchange: where I should put the private key, and where... |
Can someone explain how to find inverses in truncated polynomial rings manually (i.e. on pen and paper)?
As an example from the tutorial:
Example. Take $N=7$, $q=11$, $a=3+2X^2-3X^4+X^6$. The inverse of $a \bmod 11$ is
$a^{-1}=-2+4X+2X^2+4X^3-4X^4+2X^5-2X^6$, since
$(3+2X^2-3X^4+X^6)*(-2+4^X+2X^2+4X^3-4X^4+2X^5-2X^6... |
In block cipher modes of operation for encryption on input of a plaintext of $N$ blocks (We assume that the input size is always a multiple of the blockcipher mode: $N·16$ bytes) the size of the ciphertext is $N+1$, where the extra block is the IV.
Is there an efficient way to have fixed (parametrizable) larger length ... |
I am trying to find the protocol with the least overhead, which still meets the following requirements:
Server Authentication of server identity to client. The client has an authentic copy of the server long term public key.
Perfect Forward Secrecy.
Confidentiality, integrity, authenticity of payload, including:
Repl... |
Our assignment asks us to convert an RSA speed in bytes per second to a DES speed in bytes per second. Our professor's treatment of this ("RSA is 100 times slower than DES") seems insufficient. Could anyone explain how this conversion is calculated?
Thanks.
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That is, if I generate every possible result, and analyze the structure against, for example, a dictionary, won't that identify which of the solutions in the domain is most likely the correct one?
I realize the numbers involved, but this does ultimately reduce the problem to a hardware one. If this is not true, then I'... |
The system requires to be as paranoid as possible regarding security. One of the few contemplated changes to the current design is to use multiple encryption. First proposal was to use Serpent on top of AES-256, but after looking into it, it seems like a triple AES could also serve the purpose.
So the options are:
Encr... |
What would be the best way of encrypting small mesasages to be stored in encrypted form? (This sounds like somthing a textbook would cover, but I haven't found any references).
Let's say I have many systems producing messages (log-lines) which I would like to transfer and store centrally in a secure manner. Using off-t... |
This is a trivial question, but I had to ask:
since each generated share in a Shamir's secret sharing scheme initially consists of a pair of values (representing the coordinates of a point on the plane), how do I reduce the two values to one, so that the share that I eventually hand out will consist of only one value?
... |
I'm looking for the cryptographic equivalent of a Drivers license where the issuer can be verified, the issuer doesn't need to know who you showed the drivers license to, but also allows per-transaction privacy.
I would use the standard PKI system, but there is a hard coded certificate serial number in each cert, remov... |
Lets assume
a 4gig file that is internally made of 1 million pages of 4k bytes each (page).
the file was originally AES-GCM encrypted
these pages (or entire file) lives across the internet i.e. individual page reads are expensive/slow. (network IO operations are at page level by the way)
Is there any way to decrypt... |
I came across a marketing video here. They claim to perform AES encryption and tokenization of sensitive data, at the corporate gateway, before it leaves the company firewall destined for the public cloud. So keys and token<=>plain text mapping tables remain at gateway and cipher text/tokens live in the public cloud.
T... |
I'm studying UProve, and one of the fundamental components of this technology is based upon the relationship between
i^Q mod P = 1
Lacking a specific name I can call this mathematical relationship, where can I learn more about this equation?
I've heard that not only will the equation equal one, but there are instance... |
LIRA (Lightweight Incentivized Routing for Anonymity) is a scheme to incentivize participants in Tor to contribute resources, in particular bandwidth.
The paper talks about it being used for Tor. Can it work for other decentralized and privacy-friendly networks as well, such as cjdns?
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