31,746 reputation
560119
bio website bolet.org/~pornin
location Quebec City, Canada
age 39
visits member for 3 years, 1 month
seen 2 days ago

Cryptographer, programmer in several languages (C, Java, several assemblies, Pascal, Forth...). I also have a life.


Jul
6
awarded  Pundit
Jun
19
awarded  Nice Answer
Jun
18
awarded  Enlightened
Jun
18
awarded  Nice Answer
Jun
16
comment AES VS PRNG+HASH+XOR
Well, don't forget that when you use a hash function as a stream cipher, you are actually trusting two "pieces of software": the hash function itself, and the construction which turns it into a stream cipher. Either may be subject to design and implementation weaknesses.
Jun
16
answered AES VS PRNG+HASH+XOR
Jun
15
answered TLS - sharing 1792 bits of unidirectional keys
Jun
15
revised Trial divisions before Miller-Rabin checks?
added 666 characters in body
Jun
15
answered Trial divisions before Miller-Rabin checks?
Jun
12
comment which of these is more secure (bcrypt vs srp)
@owlstead: there are two distinct points: 1. we don't want to store on the server something which is "password equivalent"; 2. the complete processing, from the password to whatever is stored on the server, must be proper "password hashing" with iterations and salts. You can have that with PBKDF2(password) computed on the client side, and SHA-256(PBKDF2(password)) stored on the server. That way, the server-side operation is very fast, and stealing the server's database still does not grant easy entry.
Jun
6
awarded  Great Question
May
25
answered Journals to read in order to keep up to date with interesting research
May
16
answered Why do “nothing up my sleeve numbers” have low entropy?
May
11
awarded  Nice Answer
May
5
awarded  Enlightened
May
5
awarded  Nice Answer
May
3
awarded  Nice Answer
May
1
answered How to argue to a paranoid that RSA is safe?
Apr
28
answered What is the MD5 collision with the smallest input values?
Apr
22
comment Use cases for CMAC vs. HMAC?
Beware: MD hash functions like SHA-1 are built out of a block cipher, but with the data as key, which apparently allows for better bandwidth. At least we can empirically notice that the SHA-3 competition yielded algorithms which are quite faster than all AES candidates on the same hardware. Even AES-based SHA-3 candidates (e.g. ECHO) turned out to be quite faster than AES itself on the same machine.