18
votes
Accepted
What is a related key?
Related keys are keys with any mathematical relationship that leads to exploitability in the cipher. This can be a simple relationship, such as having many bits in common. This was the case with RC4 ...
- 15.5k
4
votes
Accepted
Does Wikipedia's WEP - RC4 example really demonstrate a related key attack or just an IV reuse attack?
Actually, this attack purely uses the (IV,key) pair reuse.
Actually, the page references two attacks. The first one (which is more expressly spelled out) isn't, as you pointed out, not really a &...
- 151k
2
votes
Accepted
Is rekeying attack the same as related-key attack?
No, rekeying is about changing keys: https://en.m.wikipedia.org/wiki/Rekeying_(cryptography)
And we can have attacks ob the process of changing the key without need to have related keys. Which are two(...
- 12k
2
votes
How exactly to concatenate two differential trails to form a boomerang disguisher in practice?
In this case because the trail $E_1$ begins at the stage in the cipher directly after the trail $E_0$ ends you can use $E_m$ as the identity map which preserves all differences with probability one.
...
- 26.4k
2
votes
How modern messengers encryption keys can't be hacked
Aren't they delievering by the network the same as the encypted messages?
No. At least not in the plain.
What doing it end-to-end encrypted?
Try to search for the key agreement protocol (e. g. ...
- 1,194
2
votes
Accepted
Are two keys derived from the same password vulnerable to a related key attack?
Unless the key derivation function you use is specifically designed to exploit related-key attacks, then no, it will not result in a vulnerable related-key pair. It is true that XSalsa20 is not ...
- 15.5k
1
vote
Accepted
Derrive a new key from Trusted Third Party (e.g. Kerberos) session key
In the Kerberos protocol, the authentication process involves using a shared secret key between the client and the Kerberos server to establish a session key. This session key is primarily used for ...
- 34
1
vote
RC4 Klein (or other) attack susceptibility question
There are a bunch of problems with this.
One obvious one is that your "signature" is three bytes long, which is 24 bits and subject to brute forcing.
Another is that for most cases, a three-...
- 3,544
1
vote
Accepted
secure "related-key" stream cipher
If you consider symmetric encryption schemes instead of just stream ciphers, you're looking for "key-homomorphic encryption". There has been some work on lattice-based fully key homomorphic encryption ...
- 14.6k
1
vote
Is there any practical use of reduced rounds of AES
There is not much use for reduced-round AES as a block cipher per se. AES has been carefully designed to provide appropriate security margins and 20 years of cryptanalysis show that they are just ...
- 632
1
vote
Accepted
Related-key attacks against Salsa20 and ChaCha
Perhaps the best evidence for the related-key security of Salsa20 is in the Rumba compression function proposed by the author:
$$
\mathrm{Rumba}(m_1, m_2, m_3, m_4) = f_1(m_1) \oplus f_2(m_2) \oplus ...
- 12.8k
1
vote
Will a SHAKE128 stream cipher be vulnerable to related key attacks?
No.
The underlaying permutation is well-analyzed so far as of 2018. It provides good avalanche effect even with single-bit difference; the sponge mode of operation is very well designed. In contrast,...
- 9,810
1
vote
Elliptic curve cryptography related key attacks
The answer depends on your definition of security:
Anonymity: this scheme will produce key pairs, and hence also public addresses, that are indistinguishable from random to anyone who does not know ...
- 365
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