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11h
revised Can cycle finding techniques reduce the memory usage of the MitM attack against 2DES and 3DES?
typo
11h
revised Is the Salsa20/ChaCha20 keystream generation one-way?
Distinguish nonce input from nonce
12h
revised Is the Salsa20/ChaCha20 keystream generation one-way?
Mention a notable operational drawback of Salsa20
12h
revised Is the Salsa20/ChaCha20 keystream generation one-way?
polish
17h
answered Is the Salsa20/ChaCha20 keystream generation one-way?
18h
comment Is the Salsa20/ChaCha20 keystream generation one-way?
The last two sentences are correct, but do not answer the question. Based on definition of Salsa20, $Salsa20(x)$ is an un-keyed (conjectured-one-way) function used to build the Salsa20 cipher, hence this answer does not touch the question of if the key can be found. Also three errors crept in the first sentence; actually $Salsa20(x)=x+doubleround^{10}(x)$ where $+$ is addition skipping carry every $32$ bit, and we have $1$ such addition and $10$ chained $doubleround$, rather than a chaining of $20$ times (different) additions and $doubleround$ as stated.
21h
revised Is the Salsa20/ChaCha20 keystream generation one-way?
fix negation
22h
comment Has human-generated entropy ever been a real problem?
@user2891462: Indeed, there is no claim that the OTP would have been vulnerable without reuse, and I have no proof that the initial generation involved a human (e.g. rolling and reading dices). Still, what in the end was believed to be fresh entropy was not and that turned out to be a problem; and what generated the problematic entropy as used involved humans, that are responsible of the goof. So we are pretty close to "human-generated entropy (being) a real problem"
1d
reviewed Approve El Gamal Decryption with Big Numbers
1d
reviewed Leave Closed El Gamal Decryption with Big Numbers
1d
reviewed No Action Needed Montgomery Reduction
1d
reviewed Close GMAC implementation in C
1d
reviewed Close Software applications to learn cryptography
1d
comment Is the Salsa20/ChaCha20 keystream generation one-way?
A keystream generation algorithm which key, assumed unknown and uniformly random, can realistically be found from the output keystream and input other than key, is broken by definition of key per Kerckhoffs's principles, and/or of the security objectives of a keystream generator/CSPRNG.
1d
revised Rabin-Williams, blinding and size of Integer r?
State another advantage of blinding with public exponent
1d
revised Can cycle finding techniques reduce the memory usage of the MitM attack against 2DES and 3DES?
State advantages of the technique
1d
revised Non adjacent form of an integer is unique
We no longer need repel j=1 by examination
1d
revised Non adjacent form of an integer is unique
Add missing condition on tilde j
1d
revised Rabin-Williams, blinding and size of Integer r?
polish
1d
revised Rabin-Williams, blinding and size of Integer r?
Add discussion about unusually large e, following comment