32,931 reputation
565127
bio website bolet.org/~pornin
location Quebec City, Canada
age 39
visits member for 3 years, 4 months
seen 8 hours ago

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


Nov
28
answered Where is the proof of security of Diffie's cipher?
Nov
28
reviewed Approve suggested edit on How much would it cost in U.S. dollars to brute force a 256 bit key in a year?
Nov
27
revised How can one show that an ElGamal-like signature verification scheme is valid?
added 1 characters in body
Nov
27
answered How can one show that an ElGamal-like signature verification scheme is valid?
Nov
26
answered Verilog simulation of Data Encryption Standard
Nov
25
answered How does the wider cryptographic community view non-abelian group based cryptography?
Nov
24
answered Is a book cipher provably secure?
Nov
24
comment Security of simple xor and s-box cipher?
$S$ "exists" as code which can compute a value ($S[x]$) for every $x$. One possible implementation is as a big array. Or you could have a sequence of instructions. That's equivalent here: if you have, e.g., 2 kB of ROM (code + arrays) then you have 16384 bits, and you can possibly compute only $2^{16384}$ distinct functions with that. But there are far many more possible functions with 256-bit inputs than that. Whether you use your ROM budget for code or for data is irrelevant in this computation.
Nov
23
answered Using a Non-Random IV with modes other than CBC
Nov
23
reviewed Approve suggested edit on license-key tag wiki excerpt
Nov
23
reviewed Approve suggested edit on
Nov
23
answered Security of simple xor and s-box cipher?
Nov
22
answered Message space in security definitions
Nov
22
revised Message space in security definitions
More TeX.
Nov
22
revised Message space in security definitions
TeXified equations, fixed grammar.
Nov
21
answered Trying to find a different DES encryption system explanation
Nov
19
comment What are the consequences of a MAC tag collision?
"if you MAC two messages with the same nonce": well, then, it is not a "nonce" but a "ntwice" and that's deadly enough for security, collision or no collision.
Nov
18
answered Encryption technique performance evaluation
Nov
18
awarded  Civic Duty
Nov
17
reviewed Approve suggested edit on pairings tag wiki excerpt