Questions tagged [cryptanalysis]
Analysis of individual security aspects of a cipher or algorithm, not the security of a cipher or algorithm in general (which would lean towards “algorithm-design”).
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Why does the standard SAT duplication encoding for hash collisions have structural flaws?
I've been researching why the standard approach to finding hash collisions using SAT solvers—specifically encoding $H(x_1) = H(x_2) \land x_1 \neq x_2$ by duplicating the circuit—seems to be ...
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What equation qualifies as a hidden number problem for lattice attack?
I dont know if this qualifies as a cryptographic question but the equations themselves are from cryptographic implementations.
I know this:
$x_i = y_i*d+z_i \,mod\, m$
$x_i$ is partially known
$m$ is ...
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Time memory tradeoff on block cipher with $T=M=O(\sqrt{N}).$
Given a symmetric key block cipher with an $n-$bit blocklength with $n-$bit key (in ECB mode) let $N=2^n.$
Is there a known time memory tradeoff with $T=M=O(\sqrt{N})$?
Edit: Thinking a little further,...
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Cracking affine LCG with varying increment?
My question is related to this but based on comment of Thomas Pornin.
I have:
$s_i = (a\;\!s_{i-1}+b_i)\bmod\ m$
where $b_i$ is different 32 bit odd value on every state, so its not constant like $a$ ...
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Is my recreation of the RSA-129 challenge (n, e=9007, numeric encoding) faithful to the original?
Note: A live, public implementation of this reconstructed RSA challenge
(with a solver leaderboard) is available here:
https://rsa-challenge.rf.gd
I am attempting to faithfully recreate the historical ...
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Is key recovery feasible for a 4-round 64-bit SPN cipher given 2¹⁶ known plaintext–ciphertext pairs?
I am analyzing a custom 64-bit block cipher implemented as a 4-round SPN. The cipher operates on 8-byte blocks with an 8-byte master key. The S-box, bit permutation, and key schedule are fully ...
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Related precise SAT encoding of SHA-256
Respected mathematicians, I would like to know if there is any GitHub repository that accurately converts SHA-family algorithms into SAT problems. So far, I found the SAT encoder by Saeed Nejati to be ...
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Can Pre-Computed SAT Solution Speed Up SHA-256 Preimage Search via Unit Propagation?
I've encoded unconstrained SHA-256 compression as CNF:
512 free input variables: msg_w{i}_b{j} (message bits, LSB-first)
256 output variables: ...
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Two hole hidden number problem, calculating the limits of solvability
I'm a bit stuck on the problem mentioned in the title. It seems from the ctf writeup that I am going through and trying to understand.
Here is the link for the in depth explanation:
https://ctftime....
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Speculative Question on NSA total storage capacity
This is a speculative question that may be hard to answer reliably. Apologies.
According to a Techcrunch article linked here
A stunning report in Forbes today detailed that the NSA’s rapidly ...
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Hardcore Predicate for ECDLP
The 1999 paper "The Security of all RSA and Discrete Log Bits" by Hastad and Naslund here states that any block of $O(\log \log N)$ bits where $N=pq,$ of the encrypted RSA output is known to ...
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What is the scaling difference between the most and least significant byte in a modulo-32 bits lattice?
I have studying the lattice basis construction on most implementation but i couldn't understand the difference between the scaling of the unknown part of the equation, the part we want to find in the ...
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Finding an efficient covering map secp256k1 (genus 1) to the Jacobian of a higher genus curve
Has there been any significant Research and findings on secp256k1 (genus 1) to the Jacobian of a higher genus curve, so efficient Index Calculus Algorithms can be built
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Factor multi-prime RSA
I have a multi prime 2043 bit modulus with 8 prime factors, each 256 bit.
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Best public cryptanalysis of KeeLoq
KeeLoq is a proprietary 32-bit block, 64-bit key block cipher based on an 32-bit NLFSR and 64-bit FSR that is very frequently used for wireless car keys. It clocks its NLFSR for 528 rounds to encrypt ...
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