CodesInChaos

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	5,954 reputation	bio	website	github.com/CodesInChaos	visits	member for	1 year, 10 months
1927 badges		location	Munich, Germany		seen	23 hours ago

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May 4	revised	How was the complexity of the Biclique Attack calculated? Better formatting, and replaced image with inline TeX
May 4	suggested	suggested edit on How was the complexity of the Biclique Attack calculated?
May 3	revised	Creating an encryption key from several other keys and using hash functions added 173 characters in body
May 3	comment	Creating an encryption key from several other keys and using hash functions It has been a while since I read those papers, but from what I remember they talked about low entropy sources, such as passwords, where key-strengthening is required. Whereas for inputs with sufficient entropy(say 128 bit or more) deliberately slowing down the hashing offers no benefit, since the attack this protects against is already infeasible.
May 3	comment	Creating an encryption key from several other keys and using hash functions What benefits does a slow KDF(PBKDF2&co) provide over a fast one(plain SHA-2 if no salt is requires, HMAC-SHA-2 if a salt is required), if the input has sufficient entropy? I don't see any.
May 3	comment	Creating an encryption key from several other keys and using hash functions keystreching is pretty much the only point of using slow KDFs over cheap hashes such as SHA-2. If the input has sufficient entropy, the slow down isn't necessary, since guessing the input is already infeasible.
May 3	comment	Creating an encryption key from several other keys and using hash functions "Note that key1 and key2 are random keys, not passwords, and thus key stretching is not a relevant and applicable thing."
May 2	comment	Creating an encryption key from several other keys and using hash functions It's probably unnecessary, at least I can't think of an attack that exploits it, but feels like proper hygiene.
May 2	answered	Creating an encryption key from several other keys and using hash functions
May 2	comment	Creating an encryption key from several other keys and using hash functions Do the input keys have known constant length?
May 2	revised	Can two different pairs of RSA key have the same modulus? added 264 characters in body
May 2	answered	Can two different pairs of RSA key have the same modulus?
May 1	accepted	Deterministic nonces in CTR mode
Apr 30	comment	How does the key schedule of Rijndael looks for keysizes other than 128 bit? I think you should return to the very beginning, and describe what you want to do, and what your requirements are. In particular answer all of David's questions. Once you answered all of that, we can recommend a mode, and how to use it.
Apr 30	comment	How does the key schedule of Rijndael looks for keysizes other than 128 bit? You typically put the plaintext into the plaintext parameter, and the key into the key parameter. So I see no reason to ever use a non standard key size.
Apr 30	comment	How strong is the ECDSA algorithm? And the `ECC2N` column of that draft is identical to the ECC column of the TLS spec. It'd be interesting to know, how those numbers were calculated.
Apr 30	comment	How does the key schedule of Rijndael looks for keysizes other than 128 bit? @JohnPaulParreño That makes no sense at all. AES always uses the full secret key. I don't see how plaintext size and keysize are related.
Apr 30	comment	How does the key schedule of Rijndael looks for keysizes other than 128 bit? key size and block size are independent, you could use a 160 bit key and 128 bit blocksize in rijndael. But why do you want to use a 160 bits key? Why don't you use one of the standard sizes?
Apr 30	comment	How does the key schedule of Rijndael looks for keysizes other than 128 bit? en.wikipedia.org/wiki/Key_derivation_function
Apr 30	revised	How does the key schedule of Rijndael looks for keysizes other than 128 bit? added 4 characters in body