All Questions

Filter by
Sorted by
Tagged with
0 votes
1 answer
8 views

In RFC 2313 (PKCS1/RSA) said you could recreate the Private key from 'n' and 'd', which later versions removed. Why?

RFC 2313 has this specific callout: ...
rip...'s user avatar
  • 101
2 votes
0 answers
34 views

Impossibility of uniform generation in random world

I was reading Limits on the provable consequences of one way permutations by Impagliazzo and Rudich when I got stuck on a sentence. First of all, they define a polynomial relation that is any relation ...
Pur2all's user avatar
  • 38
0 votes
0 answers
28 views

How to prove that signature hash is wrong without reveal message

Let's say we have Bob, Alice and third party. Bob make message signature hash and upload to third party, then encrypt message with Alice pub key and send it to Alice Alice receive message and decrypt ...
byXrom's user avatar
  • 3
0 votes
0 answers
20 views

How to anonymously poll for information in a small group of people?

A company wants to poll employees about their view of the company (by using a web system, say). They would like to do it anonymously, but they don't want people filling out forms more than once. An ...
user1145880's user avatar
0 votes
1 answer
48 views

Probability when representing message as a point on elliptic curve

There is a very popular method to represent a message m (number) as a point on elliptic curve over a finite field: Set $i = 0$ Check whether $m'=m\cdot K+i$ is on elliptic curve. If not, try again ...
Ape Tim's user avatar
0 votes
1 answer
30 views

How do bad actors manipulate game results in real time within 'provably fair' gaming systems?

Ive been assigned research involving online gaming companies and their use of cryptographic algorithms to produce 'provably fair' results. The largest player in the industry uses a method involving a ...
Joey Jolly's user avatar
1 vote
0 answers
54 views

Recursive NTT for Kyber

since the NTT is a variant of the DFT respectively FFT, it seems possible to implement a recursive algorithm for the NTT of Kyber with a divide-and-conquer concept. This is the reason for my question ...
TreeBook1's user avatar
1 vote
1 answer
65 views

Point doubling for a point on Elliptic Curve (15,13) + (15,13) = (2,)

Consider the elliptic curve E1:y2=x3+7 over F17 with the base point G=(15,13) I am trying to compute point double of (15,13) i.e (15,13)+ (15,13) Expected point is (2,10) , however I am not able to ...
Sudhanwa Deo's user avatar
0 votes
1 answer
93 views

Possible to encrypt message without knowing recipient public key?

Assume Bob is sender and Alice is future recipient. In ideal situation Bob know Alice public key, and encrypt message with it. But what if Bob don't know Alice public key (he only will know Alice ...
byXrom's user avatar
  • 3
-2 votes
0 answers
64 views

Factoring RSA $N = pq$ knowing that $(p+q) >> 200$ [closed]

We have $N = pq$, with $p$ and $q$ are prime numbers, and $hint = (p + q) >> 200$. How to find $p$ and $q$?
George Do.'s user avatar
0 votes
1 answer
45 views

Prove that if $e.d \equiv 1 \text{ mod } pq$ then it's impossible to have $e.d \equiv 1 \text{ mod } (p-1)(q-1)$

I am studying RSA cryptosystem and here is the question that came to my mind. Let's pick $p, q$ to be two primes and $n = p * q$. From that we calculate Euler's totient function: $$ \phi(n) = (p - 1)(...
QuestionEverything's user avatar
0 votes
0 answers
23 views

Achieving sub-block non-malleability

I have a noisy one-way communication channel where data is sent as a series of words of width n bits. Assume n is a constant roughly in the range of 16...48. I don't want bit errors in one word to ...
Stephan Walter's user avatar
0 votes
0 answers
37 views

which DH protocol is safer in communication with given condition?

I am trying to understand some concepts such as DH problem and its variants. I have the following question from the book I read. (note that I translated the question from my language to english) ...
user avatar
4 votes
1 answer
156 views

Integrating Elligator mapping with libsodium Curve25519 implementation

I'm currently working on a project where I want to map Curve25519 public keys to uniformly random noise. The main idea is that when these transformed public keys are sent over a network, an outsider ...
Safari1811's user avatar
0 votes
0 answers
23 views

Short-input (<= 128 bit), short-output (<= 10 bit) MAC

I am faced with a problem of selecting an appropriate message authentication code (MAC) for a particular application. These are the constraints: I have two 64-bit integers $r_a$ and $r_s$ as input, ...
asnfkjsdx's user avatar
1 vote
0 answers
22 views

Dealing with MITM attack in e-voting systems

I've read many e-voting papers that use El-Gamal scheme which I recall is vulnerable to man-in-the-middle attack, yet I find no discussion or even mentioning of it in those papers. -Does anyone knows ...
ShAr's user avatar
  • 152
1 vote
2 answers
106 views

What scheme is the best for combining two shared secrets?

I'm developing a program that uses a hybrid Key Encapsulation Mechanism (KEM) scheme, employing Kyber and X25519, with each producing a 32-byte shared secret. What would be the best scheme to combine ...
Zola Gonano's user avatar
1 vote
0 answers
48 views

Cannot protect GPG key using TPM2 on Ubuntu 22.04

I'm trying to protect a GPG key using the TPM2 available on my laptop, but I'm not having any success. Probably I'm doing something wrong, but I cannot figure out what this is. My system is running <...
sergico's user avatar
  • 181
0 votes
0 answers
13 views

Example of an identification protocol that 1. With a private key 2. Resistant to attack with a fake ATM 3. Not resistant to eavesdropping attacks?

Can anyone please provide an example of an identification protocol that With a private key Resistant to attack with a fake ATM Not resistant to eavesdropping attacks ?
Антон Пичушкин's user avatar
1 vote
0 answers
64 views

Which cipher is used in this UDP stream?

I'm trying to analyze a stream of communication I captured from a game. I know the keys but I don't know how to apply them. I've tried: Various AES-256 modes, splitting the message at different ...
Krab's user avatar
  • 111
2 votes
2 answers
66 views

What happens if we know that for an RSA key pair, the equation $d^e \equiv c \pmod{n}$ holds?

If we possess the knowledge that the expression $d^e \equiv c \pmod{n}$ holds for an RSA key pair, what would be the implication or consequence of this? Here, $e$, $n$, and $d$ represent the public ...
Lisbeth's user avatar
  • 487
1 vote
1 answer
43 views

Is KangarooTwelve hash function suitable for generating very large key material as Shake-256 is?

If I take a large truly random portion of data, I know that I can generate a 2048-bits key with it (assuming the random data has more entropy than the key). I read in this forum that Shake-256 has ...
alpominth's user avatar
  • 391
2 votes
0 answers
35 views

Secure mapping functions

I have two secret numbers $A$ and $B$. Both are uniformly-distributed 32-bit numbers. I need a deterministic function $f(x)$ such that $f(A) = B$. $f(x)$ must not leak any information about $A$ or $B$....
zzazzles's user avatar
  • 117
1 vote
2 answers
76 views

Constant values of ChaCha20

Is it possible to change the constant values of ChaCha20? and how it will affect the security of the cipher.
MFFC24's user avatar
  • 21
-1 votes
0 answers
24 views

How to perform addition and multiplication in Python in finite field (GF) F_{2^2}

I am trying to code something using NMDS matrices. I need to find the minimum distance of a code. How can I do the same?
Kurious Koder's user avatar
0 votes
0 answers
63 views

Is it safe to derive a secret from a signature?

Many blockchain users have wallets that hold a private key, which can interact with a website. For example, the website can request the wallet to sign a specific message. 'Do only sign this message if ...
user599464's user avatar
0 votes
0 answers
29 views

Montgomery Reduction with Even Modulus

Montgomery Reduction requires that $gcd(R,N) = 1$, where N is the original modulus and R is the selected modulus which is like $2^k,k\in\mathbb{N}$, because the computer adopts binary coding. When N ...
槿铃兔's user avatar
1 vote
2 answers
227 views

The security of using a digital signature scheme twice with randomness

Suppose $\Pi=(Gen,Sign,Vrfy)$ is a secure signature scheme, is the following signature scheme $\Pi'$ secure? $Gen'$: The same as $Gen$, output public-private key pair $pk,sk$ on input $1^n$ $Sign'$: ...
Kagura Hitoha's user avatar
1 vote
1 answer
41 views

Optimization :Garbled Row Reduction (GRR3)

In GRR3,we make the first row of the Garbled table to be zero by chosing a special value of C1. My question :Why don't we make the second row also zero by chosing a special value of C0?
asasdasdsa's user avatar
0 votes
1 answer
55 views

Chinese Remainder Theorem in a strange configuration

Normally, the chinese theorem looks like this:$$ x = a_1 \bmod n_1\\ x = a_2 \bmod n_2\\ x = a_3 \bmod n_3$$ but what to do if in my situation it looks like this:$$ c_1 = x^e \bmod n_1\\ c_2 = x^e \...
vert3x's user avatar
  • 1
0 votes
0 answers
39 views

Kerberos authentication only works with aes256-cts-hmac-sha1-96 for Windows 10 [closed]

I have a Windows 10 server joined to a RedHat IDM realm using Kerberos. When a user tries to authenticate on a Windows 10 server, the following error is shown On the IDM, looking at the ...
hypersonics's user avatar
1 vote
0 answers
45 views

Input/Output size of compression functions

I know that DES has 56 independent key bits, and that 3DES has 168 independent key bits by using 3 seperate 56-bit DES keys. 3DES also has a block size of 64 bits. If I use 3DES as the underlying ...
mjg4's user avatar
  • 11
3 votes
0 answers
59 views

Cryptanalytic attacks ASCON MAC

I am researching ASCON. I can find cryptanalytic attacks ASCON authenticated encryption and ASCON HASH, But I am not finding anything ASCON MAC. Anyone knows of any attacks, any research on this?
Nicole Foster's user avatar
0 votes
0 answers
36 views

Help With Weird Hill Cipher On Phone After Network Intrusion [closed]

Hackers Left a Hill Cipher on My Phone. I found the cipher below after experiencing a network intrusion. Decode.fr identifies it as a hill cipher. It was typed out on my phone when I was not looking. ...
JustSomeCryptid's user avatar
1 vote
0 answers
38 views

hybird proof on q-query pke classic scheme

I am reading the proof of the advantage of q-query kem attack should not be much greater than 1-query kem attack without loss of generality(for example, one time pad is secure but two time pad is ...
stem_noob's user avatar
1 vote
0 answers
58 views

Extended-Chacha20

Research paper: "Extended-Chacha20 Stream Cipher With Enhanced Quarter Round Function" The initial matrix is 6x6, but what are the exact inputs for each index, in other words, how will you ...
MFFC24's user avatar
  • 21
1 vote
0 answers
22 views

Argon2 confusion when computing J_1 and J_2

I'm implementing Argon2id from the RFC 9106 and I'm at the part where each thread computes J_1 and J_2 in order to generate indices [l] and [z]. I'm confused as to which TYPE (y = 0, 1 or 2) of Argon2 ...
Kevin Stefanov's user avatar
1 vote
0 answers
30 views

Efficient decoding a code dual to a Goppa code?

Consider a matrix $H \in GF(2)^{a \times b}$ where $b > a$. This defines two linear codes. First, we have the code for which $H$ is the parity check matrix: $$ C = \{ \mathbf{x} \in GF(2)^b | H \...
StephenJ's user avatar
  • 111
0 votes
0 answers
39 views

Unable to encrypt and decrypt using the Generalized-Feistel Cipher from Black & Rogaway paper

I am trying to implement the algorithm suggested in Section 5 of the Black & Rogaway paper titled "Ciphers with Arbitrary Finite Domains" in C++. It is a Feistel cipher that tries to ...
Drew's user avatar
  • 1
0 votes
1 answer
74 views

CBC KEY recovery when KEY=IV

We have access to an encryption and decryption server with the following implementation. How can we get the secret key by interacting with this server? ...
Sahar's user avatar
  • 3
2 votes
2 answers
69 views

Using the MAC to verify if Cipher Only attack has succeeded

I am working on an experiment to compare the efficiency of brute-force attacking block ciphers like AES and DES with reduced key sizes for different programming languages and library implementations. ...
Matt's user avatar
  • 21
0 votes
0 answers
31 views

I'm wondering if using the same one public key does not guarantee privacy in the computation of multiple data owners

Participating entity: multiple data owners, computing clouds Protocol: The multiple data owners send their data to the computing clouds, which perform the computation of the data. Privacy protection:...
user2642459's user avatar
0 votes
1 answer
40 views

Why the full r-torsion group contains r^2 many elements and consists of r+1 subgroups

let F be a finite field, E(F) an elliptic curve of order n, ...
l4rmbr's user avatar
  • 101
1 vote
1 answer
42 views

Near Maximum Distance Separable Code

I want to find the minimum distance of an $[8,4]$ Near MDS code over a finite field F_4 (NMDS Code is a type of linear code). I want to know which programming language has a built-in function that ...
Kurious Koder's user avatar
0 votes
1 answer
110 views

Additive Secret Sharing of Floating point numbers

Consider a floating point number $f$ in IEEE 754 format with sign, exponent and significand values as $f.s$, $f.e$, and $f.sig$. Given this floating point number $f$, I want to compute the shares of $...
Sumana Bagchi's user avatar
3 votes
0 answers
49 views

Are high-dimensional versions of NTRU cryptosystem more secure?

The basis for this question is a 1-dimensional NTRU cryptosystem. After some literature inspection I have found out it can be also generalised into higher algebras: quaternions (QTRU) and octonions (...
max's user avatar
  • 219
0 votes
2 answers
92 views

Performing Point Division on secp256k1 Elliptic Curve for odd Integers

I'm exploring elliptic curve cryptography, specifically on the secp256k1 curve. I've come across the concept of point division by integers using scale multiplication, my question is how can I devide a ...
Favour's user avatar
  • 9
0 votes
0 answers
42 views

Ed25519 and sealed boxes libsodium

Accidentally used ed25519 public key to create libsoidum_sealed_box. Is there any way to decrypt the data if the private key ed25519 is known?
user112852's user avatar
-1 votes
1 answer
89 views

Is it possible to deduce the input of a hash by running in reverse? [duplicate]

If i understand correctly, hashes run a defined set of operations iteratively until the original data is all hashed. Can you take a hash value, run it backward through the last step (or once, for an ...
Zekchelovek's user avatar
0 votes
0 answers
29 views

Safety of using non-encrypted hashes to identify encrypted data in a key-value store

I saw posts tangentially related to this, but not this one specifically. I'm building a content-addressable storage layer where I'd like to store the contents encrypted. The question is what is a safe ...
Loren's user avatar
  • 101

15 30 50 per page
1
2 3 4 5
597