9,834 reputation
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bio website github.com/CodesInChaos
location Frankfurt, Germany
age
visits member for 3 years, 3 months
seen 52 mins ago

Oct
23
comment Can I safely replace XOR with ADD in a stream cipher?
@HannoBinder If your stream cipher is so broken that this makes a difference, run.
Oct
23
comment Can I use the ChaCha core as a 256-bit to 256-bit one-way function?
@RickyDemer I don't know much about that, but DJB emphasized that Salsa20 is designed as a cipher, not as a collision resistant hash. He even renamed the core from "hash" to "core" to avoid misunderstandings. "The Salsa20 core does not compress and is not collision-resistant."
Oct
23
reviewed Approve suggested edit on salsa20 tag wiki excerpt
Oct
23
reviewed Approve suggested edit on salsa20 tag wiki
Oct
23
comment In RSA, what is faster attacking “d” when plaintext is known, or factoring when M is unknown?
1) Any native brute-force is ridiculously more expensive than sieving based attack. You can't even brute-force RSA-256 2) Why do you say "no plaintext available"? Since RSA is asymmetric, an attacker can produce as many plaintext/ciphertext pair as they like.
Oct
23
comment Can I use the ChaCha core as a 256-bit to 256-bit one-way function?
If you only need one-way-ness / first pre-image resistance, you should be fine, since that maps directly to a key recovery attack on ChaCha. If you need collision resistance, don't use it.
Oct
23
comment MARS and RC6 in CUDA
As a side-note: You should target ATI CPUs as well, those usually have higher performance for crypto.
Oct
22
comment What block cipher is used for CBC-MAC?
CBC-MAC is fine with variable length messages, as long as you never have one message that's a prefix of another. For example a length prefix can achieve that if you know the length of the message beforehand.
Oct
22
comment Should I trust CipherCloud?
Looks like they came up with a major cryptography break-through this month: You can use AES with a random IV. True pioneers who boldly go where no man has gone before.
Oct
22
revised Genuine encryption from only one source?
edited title
Oct
22
reviewed Approve suggested edit on What block cipher is used for CBC-MAC?
Oct
21
comment Genuine encryption from only one source?
Does a standard digital signature fit your scenario?
Oct
21
revised Genuine encryption from only one source?
edited tags
Oct
21
revised Salsa20 in Davies-Meyer mode with a fixed key (message): is it one-way?
edited tags
Oct
21
revised What is the PRG period of stream ciphers such as RC4 or Salsa20?
edited tags
Oct
21
revised Security of Salsa20 with some known plaintext?
edited tags
Oct
21
revised Is it safe to assume Salsa20 to be a PRP?
edited tags
Oct
21
revised hardware and software optimizations for Salsa20
edited tags
Oct
21
revised Fast Salsa20 in java?
edited tags
Oct
21
revised Security considerations on “expand 32-byte k”-magic number in the Salsa20 famility of stream ciphers?
edited tags