Questions tagged [related-keys]
Keys with an exploitable mathematical relationship, and the attacks they enable
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Is the CFB mode of Encryption related-key secure
I am going through the paper https://www.iacr.org/archive/fse2013/84240283/84240283.pdf where the related key security of CBC mode of encryption is well analyzed. I am concerned about whether the CFB ...
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Derrive a new key from Trusted Third Party (e.g. Kerberos) session key
Kerberos (and I assume other Trusted Third Party protocols) use (hash) an existing shared secret key to create a session key used for authentication. I read that this authentication secret key can ...
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RC4 Klein (or other) attack susceptibility question
What issues do yall see with the following in terms of key recovery and related key attacks:
RC4 used to "sign" a nonce:
3 byte nonce concatenated with 16 byte long term key > RC4 ...
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Using TEA to build a hash function
Background:
TEA uses a 128 bit master key $K_{0\ldots3}$. All odd rounds use $K_0$, $K_1$ as the round subkey, and all even rounds use $K_2$, $K_3$. One cycle of TEA applied to the block $A_i$,$B_i$ ...
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Encrypting with one key and decrypting with a related key
Given $n$-bit block cipher $E$ (and its inverse $E^{-1}$), define block cipher $E^\prime_k(m) = E_k(E_{f(k)}^{-1}(m))$ where $k,f(k) \in \{0,1\}^n$ and $\forall k:f(k) \ne k$. Under the ideal block ...
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Proof of score in a public game with a public contract leaderboard
Game:
Users stack blocks to form an unstable tower. Each time a new block is successfully laid, the game creates a score_string which is meant as proof of the user's current score. Assume each user ...
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Does Wikipedia's WEP - RC4 example really demonstrate a related key attack or just an IV reuse attack?
On Wikipedia's Related Key attacks page, there is a section about WEP as an example to related key attacks.
Encryption uses the RC4 algorithm, a stream cipher. It is essential that the same key never ...
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Related Key Attack on Schnorr Signature - Why does the challenge include $\psi = g^x$, not $y$?
The original Schnorr signature scheme suffers from a Related Key Attack (RKA) as described by Morita et al. The authors of this paper then suggest a modification to the signature algorithm to prevent ...
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How exactly to concatenate two differential trails to form a boomerang disguisher in practice?
I've been reading many papers on boomerang/rectangle attacks. The general strategy is to find two trails for a small number of rounds and then concatenate them to form a longer distinguisher. ...
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How modern messengers encryption keys can't be hacked [closed]
I dont know is this question more like reverse-engineering or cryptographic.
Why governments are hunting for encryptions keys? Aren't they delievering by the network the same as the encypted messages? ...
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Is there any practical use of reduced rounds of AES
There are lots of attacks which are on reduced block ciphers. There are practical attack on five rounds of AES-128five rounds aes broken in six minutes. I was just wondering if there is any practical ...
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Related-key attacks against Salsa20 and ChaCha
From the Salsa20 security document, DJB states that he doesn't care about related key attacks:
The standard solutions to all the standard cryptographic problems—encryption, authentication, etc.—are ...
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Are two keys derived from the same password vulnerable to a related key attack?
Background
I am currently writing a password manager application. As usual, the passwords are put in a file encrypted using a user-entered password. I'm using the NaCl library but actually it's not ...
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secure "related-key" stream cipher
Consider a stream cipher $E(k)$ which takes a key $k$ to produce a pseudo random keystream.
It should have the property that you can easily generate a set of at least 3 different keys $\{k_m, k_0, ...
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Is AES resilient to chosen plaintext with access to related keys (key expansion primitives)?
I'm interested in knowing whether a cryptosystem is broken given access to a few primitives.
$\DeclareMathOperator{\KEYEXP}{KEY\_EXP}$
$\DeclareMathOperator{\E}{E}$
Suppose that you have access to an ...
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