instruction stringlengths 32 27.2k |
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I can see that True Random Number Generators can produce some null bytes, after some megabytes of data, even 2 consecutive null bytes are produced:
$ timeout 0.5 /usr/sbin/haveged -n 0 -f - | xxd -p | grep "^0000"
haveged: command socket is listening at fd 3
Writing unlimited bytes to stdout
000010aa8070250869b3727f3f3... |
I'm currently working with an undocumented crypto offload processor that is capable of accelerating modular multiplication in some fashion. I need to figure out what operation it is implementing exactly in order to emulate it in software.
The hardware has four big integer inputs:
Multiplicand $a$
Multiplier $b$
Modulu... |
The Windows RNG infrastructure is specified in this article.
On page 4, it states that the PRNG called AES_CTR_DRBG is used (with 256-bit security strength).
According to Wikipedia, this PRNG has security problems when used with certain parameters.
Specifically:
When AES is used as the underlying block cipher and more... |
Assume there are multiple secure elements, and also multiple man-in-the-middle or malwares. How can any two secure elements authenticate each other without a third party and hard coding something in all elements? Since a hard coded code is vulnerable and can be attacked by brute force.
|
I need to generate a key and IV that will be used to encrypt multiple things over a period of time with AES in CFB mode. The decision to use AES in CFB mode is not mine to change and the key will only ever be stored in a secure way or transmitted out-of-band (i.e., not over any network where it could be intercepted)
Wh... |
How to determine the homomorphic encryption CKKS scheme's parameter bounds for correctness and 128-bit security using some specific floating-point numbers and specific computation metrics like summation or variance?
Any formal proof and theoretical process to decide the parameters like polynomial degree and so on?
|
As we know, the popular PEM format for textualizing private key binary blobs uses base64 encoding. Typical base64 codecs use look-up tables to find characters and byte values and pack them together, and this represents a memory side-channel.
While in most cases, loading of private key is completely opaque to the client... |
I'm trying to pad some plaintext to be a multiple of 16 bytes to use it as input in AES ECB block cipher.
def encrypt(plaintext):
plaintext = bytes.fromhex(plaintext)
padded = pad(plaintext, 16)
cipher = AES.new(b'0'*16, AES.MODE_ECB)
try:
encrypted = cipher.encrypt(padded)
except ValueErro... |
In LWE systems, why is it recommended to add only small error vectors to the system of equations and not big error vectors? Can someone come up with an example?
|
Consider the construction of "A Pseudorandom Generator from any One-way Function" [HILL99] in Hastad et al.
One way to proof pseudorandomness of this construction is by contradiction.
That is, an assumed PRG distinguisher is transformed into a OWF inverter (usually through an intermediate notion called pseudoentropy ge... |
I'm enhancing the venerable ent randomness test suite. And I came across this idea in On Independence and Sensitivity of Statistical Randomness Tests.
"To have more confidence in a random number generator, it is advantageous to
use as many randomness tests as possible. In this part of the study, we propose
to apply si... |
This is taken from page 16 of Stacking Sigmas
Essentially, let $0<t<\ell$ be integer values smaller than a certain prime modulus $q$. We have a set $\mathcal{X}$ with $|\mathcal{X}|=\ell-t+1$, $[k]:=\{1,2,\ldots,k\}$ and $[k]_0:=[k]\cup0$. For a given set $A\subset\mathbb{Z}_q$, define the polynomials $$f_A(X)=\sum_{i\... |
I'm looking for a textbook or article that spells out the details of Kilian's paper on the completeness of oblivious transfer for secure two-party function evaluation (2PC). Kilian's paper is in the form of an extended abstract which doesn't include many of the details. Moreover, there have been many development in the... |
Generally, we instantiate Ring-LWE with the polynomial ring $R = \mathbb{F}_q\ /\ (X^N+1)$ for prime $q$ and some power-of-two $N$.
Can we instead do Ring-LWE over the ring $R = \mathbb{F}_q\ /\ (X^N+1)$, where $q$ can be any prime power? Basically, this would mean the coefficients of ciphertexts are elements of $GF(q)... |
A prover has two pedersen commitments, $V_{a}=G\cdot a+H\cdot r_a$ and $V_{b}=G\cdot b+H\cdot r_b$, which commit the values $a$ and $b$ respectively.
The prover has another commitment $S_{\sigma}=G\cdot \sigma$ (which has no $H$ component). The verifier is provided with $V_a, V_b$ and $S_\sigma$. How can the prover pr... |
What is the minimal computation time algorithm that I can use for E2E encryption in MQTT protocol which has never been used before
|
If I talk about efficiency of system of learning with error, is it it fine for q to be composite in Z_q, the ring of integers. As when q would not be prime, Z_q will not be field anymore, won't it create problems for the system?
|
I am reading about Schnorr signature (for example, from BIP-340) and I thought, what if we add instead of multiplying for $s$? So, in the signing process it will be s = r + e + d mod n instead of s = r + e*d mod n. Verification will be the similar: calculate $s*G$ and compare it to $r*G + e*G + P$ instead of $r*G + e*P... |
There's a problem in detecting whether the sum of public key addition has crossed the cyclic group order boundary
For this example, think of public keys $Pub$ as private keys $Priv$, (private scalars), one-way converted to points on the elliptic curve.
$n$ - is the order of the group. Private keys can range from $1$ (t... |
In a lecture at my university, the following proof of correctness of RSA is given (the lecture is not mainly on cryptography or even computer science):
$m^{ed} \equiv m^{ee^{-1}} \equiv m^{1} \equiv m \ \textrm{mod} \ N$
The given reasoning is: $d$ is chosen as the multiplicative inverse of $e$ in the modulo ring $\ma... |
I am just getting started with cryptography.
After doing some research, I see that people usually advice against encryption using the same key and nonce. However if a message is too long and has to be broken up into multiple packets, how exactly does this work?
Will a different key and nonce be generated for each packe... |
Decrypt “jjjj aaa cccc ddddd” using Vigenère cipher with the key “CONVO”. I used 2 different generator and online calculator and i am getting 2 different results
|
I am interested in what the state of the art results on the hardness of the Short Integer Solution (SIS) instances are. The one I am the most familiar with (and the most discussed) is to use lattice reduction, which can be ignored. I have also found the Blum-Kalai-Wasserman (BKW) algorithm, which seems to be applicable... |
Assume that Prover have $n$ pedersen commitments ($V_{a_1},V_{a_2},\cdots,V_{a_n}$ where $V_{a_i}=G \cdot a_i + H \cdot r_{a_i}$) of $n$ elements $a_1,a_2,\cdots,a_n$. The Prover have another element $\theta$.
The verifier is provided with these $n$ pedersen commitments ($V_{a_1},V_{a_2},\cdots,V_{a_n}$) and $\theta$.
... |
According to Jack Watling & Nick Reynolds,
Ukrainian officers recalled one incident in which the Russian headquarters gave pre-emptive warning to its units of an artillery strike based on Ukrainian troops calling in a fire mission. The Ukrainian troops were communicating with Motorola radios with 256-bit encryption, b... |
From Introduction to Modern Cryptography, 6.2.1 Substitution-Permutation Networks
A description of an optimized attack on one round SPN
A better attack is possible by noting that individual bits of the output depend on only part of the master key. Fix some given input/output pair (x, y) as before. Now, the adversary ... |
A few months ago I decided to write my own custom prime number generator. One of the tests I use is a modified Miller-Rabin test that tests the number against base 2 and then only tests random odd numbers, instead of completely random numbers. I figured this might get better probability than 1/4^k for k rounds since if... |
I'm taking 2 medium-length strings (50-70 chars) and hash them using md5 to get results like d2ae4f4919a10958e2c603782f0ec1cc, then recording the first 5 symbols of the hash to provide a (unique) short key. If md5 distribution is (almost) random then would the chances of a collision be 16^5 ([0-9a-f]^5) = 2/1.048.576, ... |
Under the Wassenaar Arrangement and applicable export control law, symmetric cryptography of an (effective) key size of 56 bits or less is (generally) exempted from export control. I am forced to work within this constraint. My goal is to maximize security regardless. Encryption and decryption operations may take about... |
By going through the document: https://www.dmtf.org/sites/default/files/standards/documents/DSP0274_1.2.0.pdf
I could get that this spec will be used to verify the identify and attestation of h/w & firmware with the help of TCG_UDS spec. I want to know that do we have any other advantage of having SPDM specification?
|
Why is the signature in DSA the way it is?
I am referring to $r$ and $k$ in the Signing-Algorithm depicted below. Is it really necessary to have both, $r$ and $s$, or would it still be secure if only one of them is used?
In the Schnorr-Signature only one random number is involved, for example.
|
I am following the steps in LoRa Cloud in order to derive the PIN value using the Algorithm smtc0 (https://www.loracloud.com/documentation/join_service?url=derivation_schemes.html).
I don't quite understand how the DMKEY(i) = (hash[0]+i mod 256) | hash[1] | .. | hash[15] is derived.
|
I've been reading about ZK-STARK. There's an example that appears in several blogs. The most detailed explanation of that specific example which I have found so far is in this blog.
The description of the example (the requirement) is:
Suppose that you want to prove that you have a polynomial $P$ such that $P(x)$ is an... |
I am trying to implement ECIES properly with X25519/HKDFwithSHA256/AES-128-GCM with Node.js crypto library. It is not clear to me how to determine the input key material (IKM) to HKDF.
Initially, I thought it is okay to directly use the shared secret generated by X25519 as the IKM.
const {diffieHellman, hkdfSync} = req... |
Would either $\alpha$ or $r$ suffice as challenge?
I am aware that the signature and verification were to adapt. However, what is the motivation behind using two challenges?
|
What is the best known asymptotic/concrete complexity of modular multiplication?
Using Montgomery multiplication, if $M(n)$ is the cost of one integer multiplication of $n$ bits, then the cost is $2M(n)+o(M(n))$ (assuming comparisons and bit-shifts are $o(M(n))$. Is this the best known?
|
I have read that despite strong connections between prime factorization and DLP an algorithm for the former does not imply the latter directly. But I was reading about the number field sieve and it seemed like the bottleneck was identifying smooth norms. Wouldn't an ultrafast prime factorization algorithm achieve that?... |
The are some linearly upper bounds on Hermite's constant $\gamma_d$, such as $\gamma_d \leq 2d/3$, $\gamma_d \leq d/4+1$. So we can claim that $\gamma_d=O(d)$. There is also a rather tight asymptotical bound for $\gamma_n$: $\frac{d}{2\pi e}+\frac{\log(\pi d)}{2\pi e}+o(1) \leq \gamma_d \leq \frac{1.744d}{2 \pi e}(1+o(... |
This is not a programming question. This is to confirm whether a crypto documentation is incorrect.
I am using Rust's p384 crate. I am creating a private key from a JWK string.
In the source code, at line 85:
https://docs.rs/elliptic-curve/latest/src/elliptic_curve/jwk.rs.html#85
it says:
The `d` ECC private key parame... |
Key generation: Key Generation
Firstly, the RSA algorithm will be used to generate a public and a private key.
Generate two random prime numbers p, q.
Select RSA public key, P k such that gcd(P k, Φ)= 1 and 1< P k < Φ.
Calculate the RSA private key, Sk= P k mod Φ.
Calculate Elgamal public key, g= P k, private key, x= ... |
I was studying about how to transport keys from one HSM environment to another and it came to me that I would need some sort of transportation key so the HSM keys would be double encrypted.
How would this key be generated so it would be imported in both HSM securely? Coyld
It be used RSA or EC? Since the key could be ... |
I wrote an attack based on frequency analysis to break the substitution cipher.
The code is below by Python.
...
import random
import operator
import sys
cipher = """lrvmnir bpr sumvbwvr jx bpr lmiwv yjeryrkbi jx qmbm wi
bpr xjvni mkd ymibrut jx irhx wi bpr riirkvr jx
ymbinlmtmipw utn qmumbr dj w ipmhh but bj rhnvwdm... |
I have a series of backup files which are being generated daily and which I need to store encrypted. The files are to be used by bob as and when they need it.
I am planning to use public key cryptography with private key being held by the bob. The backup program will have the public key and will encrypt the files with ... |
I'm trying to understand CKKS (non bootstrappable) and I'm struggling with the encoding part.
I'm using the original paper , "Homomorphic Encryption for Arithmetic of Approximate Numbers
", also this notes "Lattices, Homomorphic Encryption, and CKKS"
and this blog.
I have four questions (will have sense after):
If Im ... |
I'm trying to understand the inhomogeneous SIS problem and I'm came across to a scenario that I don't know how to evaluate.
Let $A,B \in \mathbb{Z}_q^{n\times m}$ be two random matrixes and $u,v \in \mathbb{Z}_q^m$ be two vectors of small norm $||u||,||v||<\sigma$, such that
$A.u=B.z$.
How easy would be to find anothe... |
Let's say I have a public generator $G$, an unknown, private $p$ and a public point $pG$ on an elliptic curve.
Given $pG$ it's easy to construct $-pG$ by just taking the negative. But can you construct $p^{-1}G$?
|
I am given the ECDSA public key x and y coordinates below, calculate the compressed public key in HEX:
PubKey.X :
61702053028733271054209908027052318932346644879827564097906752978487519734153
PubKey.Y :
107222915356196552656214196479588207773590978294786246589469812962187242002272
How do I find the Compressed PubKe... |
I am following Vitalik Buterin's article to study zk-SNARKs recently.
I can understand the main procedure of zk-SNARKs when given example equation x**3 + x + 5 == 35. However, in cryptography, most equations contain exponents. For example, the prover may want to prove the knowledge of $a$ in $g^a=A$. In this case, an a... |
Can cryptography solve this problem?
Two people are chatting, Mr. X and Ms Y. They give each other a CRC16 hash of someone's name initials and salt a random number at the end (suffix).
Ms Y: "I love someone with the initials {53d4}".
Mr X: "Are that person's initials {da17}?"
{CRC16} -> Original String
{53d4} -> A7... |
I am a bit confused about Sponge construction and Merkle-Damgard-style ones for hashing. The only advantage I see for sponge construction is that they are secure against length extension attacks. So if the application does not mind about such an attack, Merkle-Damgard should be better, Is that the case?
My intuition is... |
This might be a silly question. But since more and more people simply use public blockchains as a secure ledger to store mutually agreed information to secure their high level applications, could we abstract blockchains as a secure ledger primitive that has the following properties:
Append-only
Tamper-proof (by minori... |
I'm trying to read about Diffie Hellman (One to One) kind of protocols for group communication. Is Message Layer Security the state of art protocol for group encryption (not necessarily chat or application layer)? I found Tree Based Group Diffie Hellman as one such handshake algorithm for group encryption, but not sure... |
From the PLONK paper.
On page 19 & ahead, the permutation check is described.
In particular, on page 20, the protocol is described.
Step 5 of the check is described as
Verifier checks if for all $a \in H$
a) $L_1(a) (Z(a) -1) = 0$
b) $Z(a) f'(a) = g'(a) Z(a\cdot g)$
However, in the actual Round where (I think) this che... |
I understand that R.x is a field element.
I don't understand why in ECDSA verification ie. FIPS 186-5 section 6.4.2 step 1, we check whether r is less than subgroup order.
If it has something to do with the curve (what?), then why in BIP340 Verification step 2 do we check whether r is less than the field order?
|
Why is the following protocol never used to share a symetric key between two parties ?
⊕ is the XOR operation.
Alice has M and wants to send it to Bob.
Alice generates K₁ randomly.
Bob generates K₂ randomly.
Alice has M.
Alice : M -- ·⊕K₁ --> M⊕K₁
Alice sends M⊕K₁ to Bob.
Bob : M⊕K₁ -- ·⊕K₂ --> M⊕K₁⊕K₂
Bob ... |
How fast are the fastest ones? Which ones have the most entropy? Which ones are the most practical ones?
I tried looking for answers on Wikipedia and also, I tried reading papers, but I am couldn’t find answers to these questions. I was looking for a recent paper that would have compared all the TRNGs, but I couldn’t f... |
Summarized Question:
In the context of JWK generation using RSA-PSS 4096bit with SHA-256, where the public exponent is "e" = 65537, is there any situation where the prime number 21863 comes in view?
Context:
To start, I'm not well versed with the mechanics of the algorithms discussed here, just the overview.
The questi... |
I want to create an application in which users can cast vote to blockchain in encrypted form using RSA. The private key will be revealed only after completion of the election.
My major use case is as follows:
There will be certain number of candidates, $c$. So voter has to choose a number from $1$ to c, lets say his c... |
I was reading the Coercion-Resistant Electronic Election paper and don't understand why the authors chose a modified version of ElGamal.
I guess that it was for security reasons. If so, what are the security issues of using a basic ElGamal scheme?
|
I am trying to solve a CTF challenge based on DES. I attached the code of the challenge to the question. So far I have noticed that the otp used for the encryption is the same for the entire session, and my idea would be the following:
Get the OTP by using choice 1
Use the obtained OTP to decrypt the ciphertext given ... |
I'm currently undertaking a course on Blockchain cryptography. And our first project is to transfer tokens from one wallet to another using client / server application. All mock of course.
This project is using the prescribed https://www.npmjs.com/package/ethereum-cryptography
The theory is this as I understand it:
C... |
Which method will generate stronger secret?
64 character secret generated by nanoid (https://www.npmjs.com/package/nanoid) with characters: 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-
e.g.: hNr3COb9fSz5qfZBCQx3GkpLVW-tbVM0E-Nl8xgcf8Js8-l6fqOIfSd6Gk-T_nkE
or
crypto.randomBytes(32).toString('hex')
e.... |
I am trying to solve another CTF challenge. The challenge consists in trying to exploit an oracle that decrypts any hex text we send (see code below). I am kind of stuck on this one as this is not a classical challenge, since the decrypted text is not displayed. My guess would be one should exploit the fact that except... |
I was looking at the security level of instances of sponge construction on Wikipedia depicted in the following image.
It seems to me that the security level for collision resistance follows the formula $\min(d/2,c/2)$ while for the preimage it is $\min(d,c/2)$. Can somebody explain why it is the case, please? I mean w... |
There's a keyed-permutation I'm playing with, $\ell_{i,x} = \pi_i(x_i)$, which is a bijection $X \leftrightarrow X$, where $|X| = 2^{256}$, and whose evaluations on plaintext inputs $x_i$ perfectly fill out a Latin-square, $L$, when an appropriate incrementing function, $\pi_{i+1} = \pi_i\mathrm{.step()}$, is applied o... |
Is anyone aware of an in-depth study of algorithms using preprocessing to compute fixed-base exponentiations? Assuming I am willing to do arbitrary computation in the preprocessing phase (but not store an arbitrary amount of data afterward), what is the optimal time/storage tradeoff here?
Note: I have read this page on... |
Say we have a very limited password space with only a 4 digit PIN, so only 10000 PIN possibilities.
Say also that the attacker has access to the stored form of the PIN.
Can breaking the PIN be made reasonably difficult by storing the PIN in a way that makes the reverse computation impossible, as well as the storing i... |
I have an application that encrypts files in the following manner (I think I can hear sighs already but bear with me):
Start with two byte arrays generated from random strings of lengths l1 and l2 (fwiw, l1 and l2 are primes)
Loop through both arrays (nested loop) and generate a third array of length l1 * l2 where eac... |
Christel Bach's elliptic curve calculator has the coordinates for the "point at infinity" be $(0,0)$. Is that just a stand-in?
|
The effectiveness of hash function attacks is typically measured in $x$ broken rounds of $N$ total designed rounds. And some constructs containing iterated hash functions include proof of work schemes, blockchains and key derivation functions. Constructs like $H^i(...)$.
What is the predicted effect on $x$ as $i$ incre... |
I am currently playing around with some of the Python FHE libraries and found out that, e.g. TenSeal (SEAL) is able to perform "only" 8 ciphertext-ciphertext multiplications on the same ciphertext (8x1 Vector) (c1 = c1*c2 in a loop) before the noise threshold is surpassed and decryption fails.
The parameters I set for ... |
I was reading the paper One-way Accumulators: A Decentralized Alternative to Digital Signatures by Benaloh and de Mare [link], and in section 4.2, they say that given $z\in (\mathbb{Z}/n\mathbb{Z})^*$ and a set
$$\{(z^{1/m_1}, m_1),(z^{1/m_2}),\dots, (z^{1/m_k}, m_k)\}$$ with $m_i \in \mathbb{Z}$, computing $z^{1/r}$ f... |
I'm designing a cipher which has key-dependent S-boxes. The procedure is like this:
Transform the key (a string of bytes) into 96 16-bit words (the high bits are ignored, but make a difference when these 96 numbers are reshuffled to make the other two S-boxes).
Start with the identity permutation [0..255].
Take it 8 b... |
Given the following conditions:
The encryption program, which uses some algorithm resembling AES-128 but with unknown modifications to real AES-128.
It uses a fixed key and IV.
It is written in Rust WITH debugging symbols but no source code is provided.
One is able to provide an input and get the encrypted output back... |
Scenario:
Consider a scenario where Server 1 stores a 600-800 KB ebook encrypted with a certain private key. Server 2, a computation-purpose server, holds this private decryption key and get access to the encrypted file. Its task involves decrypting the file and re-encrypting it with a public key using a specific algor... |
I am currently reading the paper "A 2-round anonymous veto protocol" and have run into some trouble verifying the claims made about the zero knowledge proofs presented within. My knowledge of ZKPs is relatively elementary so I am looking for guidance as to where I may be going wrong in my understanding.
The relevant qu... |
Using Fiat-Shamir, an interactive 3-round sigma protocol can be compiled into a non-interactive zero-knowledge proof in the random oracle model.
A NIZK through Fiat-Shamir is not UC-Secure due to rewinding. There are some straight-line-extractable compilation techniques, and to the best of my knowledge, the most effici... |
Use of plain random-IV's in CTR mode, without any special "nonces/counters" (or any "dedicated" bits!), can lead to problems with "partial overlaps", whereby attackers can execute known-plaintext-attacks if there is a collision in the keystreams used for encryption.
But, what if we just simply use that random IV also a... |
Can anyone point me to techniques for efficient computation of modular multiplication/exponentiation modulo a square, as comes up, e.g., in the context of Paillier encryption? The standard references don't seem to have anything relevant, probably because they tend to focus on RSA and/or elliptic-curve cryptography wher... |
I have a Windows 10 laptop with an algorithm that creates a random number using the PRNG CryptGenRandom. According to Wikipedia:
Because CryptGenRandom is the de facto standard CSPRNG in Win32 environments, its security is critical for Windows users.
However,
The specifics of CryptGenRandom's algorithm have not been... |
ECDSA and EdDSA both require the generation of a single-use value. Are there any elliptic curve signature schemes in existence which don't require nonce and maintain the usual security strength equal to that offered by the curve?
|
Is it safe (or optimal) to use a BCrypt hash directly as the key to an HMAC-SHA256? I ask because all the BCrypt hashes I will use contain the same salt, version, and cost, so the first 29 characters of the hashes will all look the same, e.g. "$2a$06$/H63GWnve78WGVBSDouFTO". I'm not comfortable with this much known str... |
In Kyber-CCA-KEM, there's a step in the Fujisaki-Okamoto transformation, where decryption failure results in a random shared secret returned from the decapsulation call.
I have a C language project currently implementing RSA-OAEP and ECDH, and I haven't reserved a PRNG parameter for the decryption interfaces, since the... |
Imagine a large array (Megabytes) that is virtually empty, i.e. contains 0 in almost all locations. But also imagine there's 1000 pseudo random locations that contain a pseudo random byte. There is no correlation between bytes nor locations. So on average, there is a random byte > 1000 bytes apart. Then the entire arr... |
(Cryptographically and hash/checksum wise consider me a rookie, as I'm rather just using algorithms.) While there are many names, not all of them are explained - I tried searching for the meaning of a couple of names, but found neither an explanation in Wikipedia articles (multiple, like English, German and French), no... |
I need to prove that given vector of commitments of length N contains N-1 commitments to zero (and one to an arbitrary number).
More formally, given vector:
$$\textbf{a} = \begin{bmatrix}
C(0, r_1) & C(0, r_2) & C(x, r_3) & ... & C(0, r_N)
\end{bmatrix}$$
I want to prove that there is exactly one such commitment, ... |
I now understand the initial key from all the round keys will be the original 4x4 block for 128-bit keys, but I do not know how it would work for something else, like AES-256 or 192. Would it be that you copy the rest of the key and put it into the second block, but what would you do with the third and fourth columns? ... |
since I already have plaintext and ciphertext why would I need the key for? what purpose would that serve?
|
Edit: One half of the answer to this question also applies to a recently asked and now deleted question regarding the impact of an algorithm which breaks DLP over integers but has no impact on factoring. It would be tricky to go pure RSA.
This is a question based on hypothetical scenarios, please bear with me.
Consider... |
Might be a bit weird but interesting scenario: I have a telegram bot and I need to authenticate users but I don't want to store any user data(at least openly).
So here's a breakdown:
I need to prove that the user has access to the bot. So there's a "timeframe" variable, an extra piece of information which might be hel... |
I want to create a shared secret from a short string (e.g. a password) which should be easy to decrypt also in the long term. Unfortunately, I have quite a hard time to make the different tools work with each other (e.g. encrypt with ssss and decrypt using an online tool like that one.)
How should one convert the stri... |
I have been looking for benchmarks on the precomputation phase of PLONK (https://eprint.iacr.org/2019/953.pdf), but found none. Is there a resource where one can get a feel for this? Either in terms of CPU cycles or in terms of asymptotic complexity.
Specifically, I am trying to estimate how big of a burden it is to up... |
It cannot be "frequent" because that implies $H$ is not really 256-bit. Are there statistical or mathematical bounds on this? Finding the inverse is computationally difficult, but what matters here is existence.
|
I know the standard algorithms for D-log. Pollard-rho, Baby-step-big-step, Pollig-Hellman, index calculus, etc.
I'm looking for fast algorithms to find a relation for the generalized discrete logarithm:
$$\prod p_i^{a_i} = 1 $$
That is, given $p_i$, find some non-trivial $a_i$ for the above relation.
What are the curre... |
I'm new to cryptography and I was trying to find key to an intercepted vigenere ciphertext using ciphertext-only attack, I'm following book "cryptography and network security" by Forouzan.
The book introduced some complicated formulas for finding Mutual Index of Coincidence but I didn't get it.
This was mentioned in th... |
I am working on an investigation on TLS 1.3.
I've came across an article of qacafe where they shared a TLS 1.3 handshake sequence. Wireshark capture. In this capture you see that in the Client Hello a key_share is being send where it is "guessing" which cypher suite to use. This saves some bytes. by not having to send ... |
If we have a scheme for inner product predicate encryption (IPPE), then can we claim that we already have designed an attribute based encryption (ABE) scheme; So we do not need to design an ABE again. I mean, is IPPE more general than ABE?
What about predicate encryption (PE)? I think PE is more general than ABE, Righ... |
Suppose I have some ZK proofs that were turned non-interactive using Fiat-Shamir heuristic. So I need to generate the challenge value deterministically using some data shared between the prover and the verifier. Different proofs require different challenges of varying size, so using a fixed-output hash is not very conv... |
Is there a cryptographic function that employs two locks: first 'Lock A', and then on top of that 'Lock B' but it permits unlocking 'Lock A' before 'Lock B' to read the message?
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Does AES-GCM take replay attacks into consideration?
If an attacker intercepts the AES-GCM secured message and gains access to the initialization vector (IV), can they inject falsely fabricated data (ciphers) or replay past data (replay attack) to confuse the recipient? (Since the IV is also sent along with the messag... |
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