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I'm trying to understand the specification behind doubleratchet algorithm, item 2.4. Double Ratchet.
According to wiki:
A client renews session key material in interaction with the remote
peer using Diffie–Hellman ratchet whenever possible, otherwise
independently by using a hash ratchet.
What does impede Signal pro... |
I'm working in some homomorphic encryption for my Ph.D. but I'm not of the field... So I'm possible going to ask a really simple question that I'm struggling to find an answer on the internet.
Basically I'm using an scheme to encrypt some input (a vector of doubles/integers), change one bit (bit flip) to the encoding/e... |
The LWE conjecture states that, given $A \in \mathbb{Z}_q^{m \times n}$ and $A x + e$ for $x \in \mathbb{Z}_q^n, e \in \mathbb{Z}_q^n$ it's difficult to recover $x$, given that $e$ is sampled from a distribution concentrated around $0$. This might be a uniform distribution on $\{-\delta q, -\delta q+1, \dots, \delta q\... |
Is there any hardware implementation of Shamir's secret-sharing method available? I have only go the following two implementations in the existing literature.
Paper 1
Paper 2
Anything more in the GitHub or any other spaces especially in GF(2^x)? Any open-source hardware implementation directed towards FPGA will be ap... |
I am new to lattice-based cryptography
May I ask that for a lattice-based encryption
$$enc(m) = A^{T}R+m \bmod q$$
If I set the $q$ to be able to decrypt to $m$ (and suppose the bound of $q$ is tight over the bound of error and secret chosen from LWE)
But if I need an operation that takes a constant $p$, and multiply $... |
Suppose we manipulate the zeroth byte of AES state after the 9th round ShiftRow operation and we want to see its effect on the ciphertext. The propagation of the error effect is demonstrated in the figure.
I have written the equations of each step in the order below and obtained the equation of $V[0]$ in terms of key ... |
KeePassXC supports Argon2, which is great for security. However, there's a quirk that's been bothering me. Every time I save modifications to the database, it seems to stretch (derive) the key again, resulting in a 10-second delay. I should clarify that I'm perfectly fine with the 10-second delay when I type my passphr... |
based crypto
And I would like to use the lwe estimator to calculate bound for ring LWE
Found in this issue It seems to me I can set up parameters like params = LWE.Parameters(n=2^14, q=2^438, Xs = ND.Uniform(-1,1,n), Xe=ND.DiscreteGaussian(3.19)
My first question is that does "n" mean the terms of the polynomial ring... |
Suppose $F_s$ be a family of keyed pseudorandom functions. Define $F'_s(x)=F_x(s)$. Is $F'_s$ a family of pseudorandom functions? It seems false but I am able to give a proof assuming $F$ is constructed from a length doubling PRG. It is essentially the same proof as construction of PRF from PRG. I don't know if this pr... |
Assume you have implemented the S-box and Inverse S-box of AES as code (or hardware) instead of a lookup table copy-pasted from the AES standard. An obvious test you want do is to check that S−1(S(B)) = B for each byte B. However, this only proves that S−1 is an inverse of S. What do you need to check to make sure that... |
I am trying to understand the two main hard problems that have been explored in the context of homomorphic encryption: Learning with Errors Problem (LWE) and the Approximate-GCD (AGCD) problem. I have some idea of the LWE problem and its variants such as the Ring-LWE. Recently, I have been reading about the Approximate... |
How can we convert a lattice-based signature (like based on Fiat Shmair with abort e.g. Dilithium) to R1CS?
|
In Section 5.2.1 of the Kyber documentation, it states that the BKZ block size of 413 was chosen using the tool from this paper, i.e., this tool. How was the block size derived from this? Currently, inputting
n=512
m=512
q=3329
D_e = build_centered_binomial_law(2)
D_s = build_centered_binomial_law(3)
building a DBDD i... |
for a research project, i am currently looking for a way to manipulate the digital signature of a HTTPS TLS message flow. More specifically, i am trying to create a working example for a malicious webserver in order to show a client-side exploit of CVE-2022-21449 ("Psychic Signatures") for a research paper.
In order to... |
Computing the signature of hello.txt file which has the text hello in it, here is done in two steps:
openssl sha1 -binary -out hash hello.txt
openssl pkeyutl -sign -inkey private.key -in hash -out signed -pkeyopt digest:sha1
First we'll get the digest value in the hash file, then this file is signed getting the signed... |
I will describe my problem high-level, and not ask a very specific cryptographic question, since I am open for general suggestions as well. So in my question I will only speak about "security keys" not about any specific algorithms or key types.
I have a License File A, which I need to distribute. On the client side, t... |
can secrets be deciphered from the proofs generated with ZK-Snarks if a quantum attack were plausible?
I understand the concern that ZK-snarks and some of their cryptography may be broken by quantum computing in the future.
My question is whether with the proofs generated an attacker could reveal variables of the equat... |
Consider Sponge construction where capacity part of state is feed-forward and xor-ed into next state.
${state}_{i+1} = F({{state}_i}^{rate} || {{state}_i}^{capacity}) \oplus (0^{rate} || {{state}_i}^{capacity})$
Would there be any security improvement from this?
Would it improve preimage and 2nd preimage security?
Th... |
I need to select a key derivation function that will likely be used in contexts that I haven't anticipated. It will run on very low-end devices (think potato-powered IoT sensor with a bulk cost of a fraction of a cent). It will also run on higher-end devices that have the luxury of a hardware AES accelerator (costing a... |
I understand that an elliptic curve $E$ over a field $K$ has an associated twist, that is another elliptic curve which is isomorphic to $E$ over an algebraic closure of $K$.
Which cryptographic benefits do twists of elliptic curves bring?
|
What technique is used in the Off-The-Record protocol to implement authentication and message validation? And what is the difference between this technique and Multi-Designated Verifier Signatures?
As far as I understand it, the OTR protocol uses digital signatures and HMAC for authentication for one-to-one communicat... |
IND-CCA is an abbreviation of "Indistinguishability under chosen ciphertext attack" and generally, an adversary carrying out the chosen ciphertext attack is given a decryption oracle only. However, in the IND-CCA game, the adversary is allowed to make both encryption and decryption queries in the pre-querying phase.
Wh... |
The MAC scheme should not be using any primitives like PRG, PRF or PRP. Ok what could be possible solution if we ignore the statement "
|
Here's my current understanding of how ECC works.
There is a recipient and a sender - Alice and Bob and each has a public and private key - (Alice's private key is denoted by a and public key is denoted by A and likewise for Bob).
They have a publicly available curve and a publicly available starting point P.
Alice the... |
The secure multiparty computation framework SecureML 1 has proposed a truncation protocol for decimal arithmetic in the integer field.
As mentioned in this paper,
In field $\mathbb{Z}_{2^l}$, $x\in [0,2^{l_x}] \cup [2^l-2^{l_x}, 2^l)$, ...
Why is this representation employed? How can we interpret it?
|
Using a prime order subgroup prevents mounting a Pohlig–Hellman algorithm attack. Meanwhile, secp256k1 doesn't use a prime order subgroup.
What is the idea behind not using a prime order subgroup?
How does it prevent the Pohlig–Hellman attack?
|
I know that $m =m^{ed} \bmod n$, and there is Euler's $a^{\varphi(n)} = 1 \bmod n$, but how do we derive that $ed=1 \bmod(\varphi(n))$ holds for all m. Where does that equality come from? Couldn't find a proof for that.
|
As an example could be XTS with a 512-bit key that treats the key as one 128-bit key and one 348-bit key.
As to why I'm asking it's because XTS runs on one large key that it treats like two keys. Currently, the XTS splits the key in half producing(if we were to use the example above) 2^256 + 2^256(2.3158418e+77) possib... |
I am new to cryptography and I am trying to find a way to measure ciphertext entropy of encryption algorithms such as AES, Chacha20, etc for a school project. Is there any way to do it on Python? I read that the scipy library has a section for measuring entropy but I have no idea if this is recommended or even usable.
... |
I got two audio files one is encrypted and the other file is a part of the plaintext. I want to extract all the plaintext. I am using the AES-ECB mode, the size of the block is 128 bits and the start of the extracted plaintext is not aligned with the start of the cipher text.
So I need to align these two audio files. I... |
I came across the Solana network utilizing sha256 as a "proof of history". They are using it as a pseudo-VDF (verifiable delay function). The reason it's pseudo is because verification is done by full-effort recompute in parallel using intermediate values.
I am curious whether or not the way sha256 is implemented on mo... |
The description of bootstrapping in Section 5 of the BFV paper (https://eprint.iacr.org/2012/144) is somewhat challenging to grasp, and I have two specific questions:
The author mentions that if the norm of $\mathbf{v}$ is restricted such that $\|\mathbf{v}\|<\Delta / \mu$ for some $\mu>2$, it allows us to largely dis... |
According to my previous question the proofs cannot be broken by quantum computation, you cannot obtain the witness of the generated zk-snark proof.
link to my previous question.
Now if the concern is that the proofs can be forge, we could add difficulty by using chain integrity proofs:
our circuit should have an outpu... |
Authenticated Encryption with Associated Data (AEAD), such as AES-GCM, is a form of encryption that has a "built-in" integrity verification. This means that if the encrypted message is modified in any way, then this will be detected (with very high probability) in the decryption process and the decryption is going to f... |
I am new to lattice-based cryptography, so sorry that this question might seems stupid
May I ask that how can I choose the BGV parameter of ciphertext with plain text in mod 128, and error in gaussian distribution of std 3.19 and secret key in uniform distribution from -1 to 1? Do I need also need to take into account... |
I am new to Cryptography and I know there are better ways to test a cipher's effectiveness out there but in this case I am trying to test a cryptographic algorithm's(AES,xchacha20,twofish) hamming distance and avalanche effect for a school assignment/paper. Basically encrypting 50 files containing almost the same conte... |
I read the Wikipedia Page on ciphertext indistinguishability. Here it gives the following outline of the IND-CPA game:
The challenger generates a key pair PK, SK based on some security parameter k (e.g., a key size in bits), and publishes PK to the adversary. The challenger retains SK.
The adversary may perform a pol... |
According to Wikipedia, PRF is an abbreviation for Pseudorandom function family. But this answer says that PRF means Pseudorandom Function. Does that mean that a Pseudorandom Function is the same as a Pseudorandom function family? Or is the abbreviation PRF used inconsistently?
|
I am attempting a to simulate an 'Enigma M3' machine. As I understand it, the M3 is internally wired as:
Name
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Notch
I
EKMFLGDQVZNTOWYHXUSPAIBRCJ
Y
II
AJDKSIRUXBLHWTMCQGZNPYFVOE
M
III
BDFHJLCPRTXVZNYEIWGAKMUSQO
D
UKW-B
YRUHQSLDPXNGOKMIEBFZCWVJAT
NOTE: I've only included the ... |
It is well-known that AES-GCM requires the IV to be unique for each message that is encrypted with the same key. If the IV ever repeats, with the same key, then AES-GCM fails catastrophically. Now, what if we used a fixed IV (e.g. all zeros), but instead used a new random AES key for each message? The random (per-messa... |
On Wikipedia, they give the following definition of PRF:
A family of functions,
$f_s: \{0,1\}^{|x|} \rightarrow \{0,1\}^{\lambda(|x|)}$,
with $x\in \{0,1\}^*$ and
$\lambda:\mathbb N \rightarrow \mathbb N$,
is pseudorandom if the following conditions are satisfied:
Given any $s$ and $x$, there always exists a polynomi... |
During one of the seminars at my university on Cryptography, the presenter said that while computing $x/y$ over Finite Rings $\mathbb Z_{2^\ell}$, there exist some problems such as:
$y^{-1}$ may not exist as over the ring $\mathbb Z_{2^\ell}$, only odd numbers have inverses and even numbers don’t.
I understand this... |
How would knowing a clear byte value of the decrypted data affect a brute force attack on an AES-128 encrypted message ?
i.e. If I knew the 1st byte should decrypt to 0xff
OR I knew that every 100 Bytes should decrypt to 0xff ?
OR I knew every 100 2 bytes should decrypt to 0xff00 ?
|
The question is mainly stated in the title. I had to do a refreshment on public key cryptography. The algorithms are pretty straightforward however, I always stumbled upon this question. Is it in order for the same message to be able to be signed with a different signature each time, like some kind of nonce?
P.S. I'm t... |
If I convert a long sentence (>50 characters) to c and use the result (128 hex characters) as a password, how secure is it?
|
I am currently reading Homomorphic Encryption Standard. May I ask that for table 1 in the link, why increasing the security level will yield a smaller ciphertext size (log q)?
I attach a screenshot below
Thanks a lot!
|
I've been checking the NIST PQC documents to find the requirements about the minimum required numbers of signatures to be generated with a signature scheme:
NIST call for proposals
Call for Additional Digital Signature Schemes
I think the other schemes don't have this limitation, but Hash Based Signature schemes do h... |
In the Kyber Algorithm specifications document, chapter 5.1.2 primal attack, it says that:
Given the matrix LWE instance $(A,b=As+e)$, one builds the lattice $\Lambda = \{x\in \mathbb{Z}^{m+kn+1}:(A\vert I_m\vert -b)x=0 \,mod \,q\}$ of dimension $d=m+kn+1$, volume $q^m$, and with a unique-SVP solution $v=(s,e,1)$ of n... |
Deepfake technology has become very difficult to tackle due to sophisticated machine learning algorithms. Now, even when a journalist or bystander provides photo or video evidence, the culprit denies it, claiming that it is the result of deepfake manipulation. Can TEE (Trusted Execution Environment) cryptography techno... |
I'm looking to prevent a DDoS attack on a web service, by making the cost of performing an attack prohibitive. Typical users will only need to call out it once a day, and can afford to spend a few CPU cycles on each call, but I want to make it so an attacker making millions of calls would have spend considerably more t... |
I'm currently reading the 'A Graduate Course in Applied Cryptography' paper written by Boneh and Shoup. More precisely, I'm reading the chapter about 'Elliptic Curve' and I'm stuck at the exercise about scalar multiplication.
I managed to answer equation 15.37 but I'm stuck for equation 15.38.
What I did so far.
First... |
I'm trying to solve this problem.
I tried this. Consider distinguisher $D$ such that
$D(c) = \begin{cases} 1 & \text{If there is at least $2\log_2n$ consecutive 1's} \\
0 & \text{o.w.} \end{cases}$.
Since $G$ is PRG
$$|\mathbb{P}[D(G(U_n)) = 1] - \mathbb{P}[D(U_{\ell(n)}) = 1]| \leq \varepsilon(n)$$
where $\varepsilon... |
I was wondering if by now any poly-time Karp reduction between GapSVP and GapCVP (exact or approximate) exist. I know of the Cook reduction between these problems, but I couldn't find anything about many-to-one reductions between these problems.
|
I'm learning about the scheme of a distributed data clean room. It appears to be similar to an MPC (Multi-Party Computation) framework. What is the difference between them, and why does it run faster than a normal MPC?
https://www.snowflake.com/blog/distributed-data-clean-rooms-powered-by-snowflake/
|
I have three numbers x, a, and c, where both a and c are odd numbers. The number x is the output of the following function:
$$
x = a^b\!\!\!\!\!\!\!\mod{c}
$$
I am attempting to determine whether the input exponent, b, was an odd or even number based on the knowledge of the three values, a, c, and x. Is there a way to ... |
Over the past few months, I have been reading and trying to understand how ECDSA works and how safe is it.
So now something does not add up between its signature verification and generation.
But maybe its my code so here:
import ecdsa
import random
import libnum
import hashlib
import bitcoin
from ecdsa import SECP256k1... |
The question is mainly stated in the title. We don't consider any other changes to the scheme except for the following:
We replace $S = H(R,A,M) \cdot a + r$ with $S = H(R,M) \cdot a + r$.
My thoughts are that since A is the public key, it is redundant since $a$ is still present on $S$ and $A$ is still used in the veri... |
$$g^a = c \bmod{N} \text{ }\rightarrow \text{ }G_{i_1}G_{i_2}G_{i_3}...G_{i_n} = C \bmod N $$
At the Discrete Log problem we try to find the exponent ($a$) of a generator ($g$) over a finite filed. e.g. $$g^a = c \bmod{N}$$
We assume everything except the exponent is known. This also includes the factorization of $... |
I am reading the BGV paper. On page 18, after addition, the protocol will also refresh (modulus and key switching), may I ask why is this required? It seems to me that I can still use the same secret to decrypt the added ciphertexts.
$\text{FHE.Add}(pk, c_1, c_2$): Takes two ciphertexts encrypted under the same $s_j$.... |
I am currently studying the cryptanalysis of Speck, but I am feeling confused about the addition in Speck. I am not sure whether the addition in Speck is done through n-bit addition over $GF(2^n)$ or addition modulo $2^n$. I have learned that the elements of $GF(2^n)$ for any $n$ can be represented as $n$-bit bitstring... |
Could you not use zk-STARK for a post-quantum signature scheme?
Your private key is a random symmetric encryption key, your public key is the hash of the encryption key.
To sign you run an algorithm to encrypt a hash of data-to-be-signed with your private key and hash your private key to obtain the public key.
The sign... |
In elliptic curve cryptography using the secp256k1 curve, how can I determine the number of times the base point $G$ has been multiplied to derive a new point? The formula is as follow:
$k * G = Q$
Where:
$k$ is an integer
$G$ is the base point on the curve
$Q$ is the resulting point after multiplying $G$ by $k$
How ... |
Studying for Cryptology and came across a presentation regarding on "Integrity vs Authenticity" where the discussion briefly mentions how Encryption "does not provide integrity or authenticity"?
Why is this the case with Symmetric Encryption for example? Or is it with Cryptology in general? Not much details are mention... |
I would like to know if there are non-lattice based NIST submissions that are affected by a polynomial time algorithm to Shortest Vector Problem. Are there known reduction from (e.g.) code based cryptography to SVP or any other non-lattice cryptographic system to SVP?
|
Does signing always involve encrypting a hash or can we call private key encryption of an unhashed message signing too?
|
I can't seem to understand what $A_{N,q}$ represents in this paper (Section 2.1 - Notations). More specifically, I'm struggling to grasp the meaning of $\mathbb{Z}_q[X]/(X^N + 1)$. Could someone please explain it to me?
$\lfloor . \rfloor$ represents the ceiling function.
$\mathbb Z_q = \mathbb Z \cap [-\lfloor\frac{q... |
Do there exist cryptographic primitives that have proved that they cannot be constructed from CDH assumption only but can from DDH assumption?
More generally, do there exist cryptographic primitives that must require decisional problems for their security?
|
For a project, I am writing Enigma and Bombe simulators in Python.
I have coded up both and so far so good.
My Enigma simulator gives the same results as the online simulator here:
https://people.physik.hu-berlin.de/~palloks/js/enigma/enigma-u_v20_en.html
But now I am using my Bombe simulator to find key settings with ... |
According to the author of the original paper[1],
Verkle Trees basically let you save space (typically bandwidth, which
can be expensive) by replacing a secure hash with a vector commitment
scheme, making the tree shorter and fatter with some branching factor
$k > 2$. This saved bandwidth comes at the cost of some ext... |
Besides the limited nonce size of 96 bits, are there any other weaknesses to the GCM mode of AES?
I am creating a password vault and am trying to narrow down my options of encryption schemes.
Also, is this a safe and secure implementation of AES-GCM?
public static async Task<byte[]> EncryptAsyncV2(byte[] plainText, byt... |
It's a very standard move in a game-based security proof to have a transition in which we "abort" on some event such as a hash collision; the two games are identical apart from the abort step, and we add the probability of the abort to the advantage term at the end. Example: https://eprint.iacr.org/2023/1368
I'm curiou... |
I have the following problem.
Here's a rephrased version of your problem, keeping the LaTeX commands unchanged:
We are given $n \in \mathbb{N}$, $p, q \in \mathbb{N}$, and $y \in \mathbb{N}^{n+2}$. Assume the existence of a constant $K$ and a vector $x \in \mathbb{Z}^{n}$, fulfilling the relation:
$$y_{j+2} = \left((K ... |
SHA-2 makes use of non-ARX non-linear operators such as the Choice and Majority functions:
\begin{align}
\mathsf{Ch}(E,F,G) &= (E \wedge F) \oplus (\neg E \wedge G)\\
\mathsf{Ma}(A, B, C) &= (A \wedge B) \oplus (A \wedge C) \oplus (B \wedge C)
\end{align}
Why is it considered an ARX cipher the same way other primitives... |
In Jeffrey Hoffstein, Jill Pipher, and Joseph H. Silverman's book An Introduction to mathematical cryptography, 2nd edition, page 78, there is:
If we are working in the group $\mathbb F^∗_p$ and if we treat modular addition as our basic operation, then modular multiplication of two $k$-bit numbers takes (approximately... |
I have seen other answers here on Stack Exchange regarding MAC-Then-Encrypt vs. Encrypt-Then-MAC (and this article regarding MAC-Then-Encrypt padding oracle attacks on SSL) as well as generic Hash-Then-Encrypt vs. Encrypt-Then-Hash, but in this case I am seeking insights on the security aspects of a specific authentica... |
Christof Paar explains in his lectures that Elgamal encryption scheme picks the private key from $\{2, \ldots, p-2\}$, is there a reason for excluding the last and first elements?
|
I know the theory of lattice attacks against ECDSA from Minerva. So, as far as I can understand, the lattice that they build is
$$
L_M = \begin{bmatrix}
2^ln & 0 & 0 & \cdots & 0 & 0 & 0 \\
0 & 2^ln & 0 & \cdots & 0 & 0 & 0 \\
0 & 0 & 2^ln & \cdots & 0 & 0 & 0 \\
& \vdots & & \vdots & & \vdots \\
0 & 0 & 0 & \cdots &... |
I want to test a C implementation of Hash_DRBG—which test_demo.c file I will modify to produce random binaries indefinitely to STDOUT as to be used by piping its output—using DIEHARDER for a research. I want to base my research around this research, however I don't find any mention of how it's seeded. NIST have several... |
I'm building a service, that works as the cipher and decipher for instant messages. It works by following the following steps:
The sender encrypts the text(not long, mostly chatting messages) using a public key;
The sender saves the encrypted text to a server. The server generates a customized URL
schema as the link t... |
In the implementation of centered binomial distribution of crystals-kyber, the authors load 24-bits of buffer to a 32 bit integer and then they and the answer with 0x00249249. The complete operations are below:
t = load24_littleendian(buf+3*i)
d = t & 0x00249249
d += (t>>1) & 0x00249249
d += (t>>2) & 0x00249249
Can s... |
If it is could you give me a paper that states it is possible?
Thank you
|
Is there a curve that supports both?
Or are there two curves that can be mapped between using a 2-isogeny that support pairing checks on one and Montgomery ladders on the other?
Is there a paper on it?
|
Are there two curves that can be mapped between using a 2-isogeny that support pairing checks on on curve and Montgomery ladders on another?
Is there a paper?
|
Given an Ed25519 key pair, can you think of any way to get to the same X25519 public key from the Ed25519 secret as from the non-clamped(!) Ed25519 public key?
Ed25519 secret
\=> Ed25519 non-clamped public
\=> X25519 public (transported)
v^ should match
/=> X25519 public (... |
This is a follow up question to:
Bit Flipping Attack on CBC Mode
which demonstrates that a bit flipping attack with a known IV is possible on CBC mode.
Is it safe to assume that the bit flicking attack is not possible if the attacker doesn't know the IV?
|
I am currently doing the elliptic curves and I'm stuck for 8 hours without finding solutions. I under stand the process of double and add but don't know how to obtain 5 * 8P = 4OP =11 P. 11 P was in the answers my teacher gave me please someone help.
|
Why Oribatida uses previous capacity $V_{a+m-1}$ instead of current capacity $V_{a+m}$ for rate masking?
|
I'm working on a local, client-side password manager. I want to hash a master password with argon2 to store it safely in an SQLite database. This will be how a user could login and be authenticated. (Also I'm using Rust for this project, with sodiumoxide, a rust wrapper for libsodium)
I was also planning on somehow usi... |
Is it possible to extend the general concept of homomorphic encryption:
$$f(m_1)\cdot f(m_2)=f(m_1+m_2)$$
to:
$$f(m_1)\cdot g(m_2)=f\cdot g(m_1+m_2)$$
is it further possible to construct the scheme in a way that the key (if compromised) $f\cdot g(\cdot)$ does not allow drawing conclusions on the encryption keys $f$ or ... |
I am studying the Shortest Vector Problem and I have some troubles understanding the actual Lovàsz condition used in the LLL algorithm.
On the one hand, the original LLL article, the Springer book "The LLL Algorithm" and A Complete Analysis of the BKZ Lattice Reduction Algorithm state that the LLL algorithm outputs a r... |
I'm learning PHP and I've come to the password hashing section of a course I'm following, but it's not explained well enough for my liking.
It seems that when using the crypt function, and using the CRYPT_BLOWFISH hash type, I get a resultant hash that contains the salt itself.
For example with the following code:
$sal... |
Suppose in Patterson's algorithm for the correction of binary Goppa codes, we wish to compute the syndrome polynomial when the defining polynomial is $g(x) = x^{4} + x + 1$, and the error polynomial is $e(x) = x^{3} + x^{14} + x^{7}$ where these are polynomials over $\mathbb F_{16}$ where we write $F_{16} := F_{2}[\ga... |
Currently, I am using AES-GCM to encode and decode a plain text file. The key is derived from a plain text password using PBKDF2 and a random salt with SHA-256. However, I have been thinking and came to the conclusion that the resulting ciphertext is only as secure as the plain password and its entropy, plus the number... |
I am looking for a secret sharing algorithm which accepts a large array, some elements of which are real shares and the rest are fake. The algorithm should satisfy the following conditions:
If all the real secret shares are present in the array (in whatever places, in whatever order), then the result of the algorithm ... |
Given a hash cipher f(sha1($pepper . $plaintext)) where
f is some transformation to an 11-byte string
pepper is 24 bytes long with a character space of 62 (and is not unique for a given plaintext)
plaintext is known for a set of ciphertexts
Is it possible to determine what the pepper is?
|
Is my summary understanding of current (classical) Digital signature standards essentially correct? I may be totally wrong.
DSA is no longer to be used for new signature generation just for checking existing signatures.
EdDSA is to be used for new signature generation.
Question: Does this mean all (most?) current stand... |
Just like picking one of the papers in a bowl is used to anonymously distribute a given set of numbers among individuals which lets nobody (including the person who distributes them) know who got what. Is it possible to achieve the same with cryptography.
The requirements in a setup where there is 1 distributor and "n"... |
Alice and Bob fix a largish $n$, say $n = 1000$, and they publish a simple, undirected graph $G$ on $n$ vertices (more precisely, its adjacency matrix, or a similar form of representation). Moreover they publicly agree on some hash function $h:\{0,1\}^*\to \{0,1\}^{1024}$ (or some other constant number of output bits).... |
Does anyone know an article that explains Fortuna algorithm for people without cryptographical background? If not, I would like to have an explanation because I don't manage to understand it.
|
Digital Signatures use an asymmetric algorithm, meaning that if I want to apply a digital signature to a document I sign it with my own private key and send it to the recipient.
The recipient, thanks to the public key, can already verify that the message really comes from me: a man in the middle could have intercepted ... |
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