637 reputation
112
bio website
location Brittany, France
age
visits member for 1 year, 4 months
seen 7 hours ago

Dec
9
comment Does it necessary the public key is prime number in RSA algorithm?
A good answer to this similar question could help you: crypto.stackexchange.com/questions/20324/…
Dec
8
revised Question about Delerablée's Identity-based Broadcast Encryption
added 210 characters in body
Dec
8
answered Question about Delerablée's Identity-based Broadcast Encryption
Dec
6
comment DES key complementation property
Give a look of Fact 7.87 of the Handbook of Applied Cryptography: cacr.uwaterloo.ca/hac/about/chap7.pdf
Dec
6
comment DES key complementation property
I'll guess, but you should verify, that means swap 1 to 0 and 0 to 1.
Nov
30
comment Generation of strong primes
This does not answer your questions but you might find it quite interesting. crypto.stackexchange.com/questions/15744/… I had the same question some time ago and find out, thanks to the answer, that is not necessary to use strong primes for large RSA keys.
Nov
26
comment Elliptical curve cryptography key generation time
@poncho: I agree, that was more a general comment on key generation that focused on this case, I was planning to do a survey/list on faster algorithms but your answer came before! ;-)
Nov
25
comment Elliptical curve cryptography key generation time
Usually, even a naïf algorithm is OK. The key-generation algorithm is run only once. Btw it exists some way to speed up the scalar multiplication.
Nov
24
answered El gamal correctness
Nov
24
comment El gamal correctness
It is quite easy and straightforward. Could you tell us more about the problem you encountered? Could you try to write down your computation to verify correctness and show us where you stop?
Nov
19
comment AES - Encrypting multiple blocks of files
No. It means that you don't pad the plaintext if its size is not an integer multiple of the bloc size
Nov
19
comment AES - Encrypting multiple blocks of files
Using a standard crypto library you get access to the many chaining modes. You need one iv per file.
Nov
19
comment AES - Encrypting multiple blocks of files
using a "predictible" IV (as result of a hashing function) coupled with the CBC mode is secure? I thought I read about some attacks in that case.
Nov
19
comment Modes of encryption for hard drives?
CodesInChaos, any pointer to this attack and context? I'm really interested
Nov
19
comment DHE key exchange. Is it really secure?
What do you mean?
Nov
19
revised DHE key exchange. Is it really secure?
added 259 characters in body
Nov
19
answered DHE key exchange. Is it really secure?
Nov
16
comment Checking both Quadratic residuosity and Jacobi symbol simultaneously and efficiently
Sorry, I think I took a mental shortcut, actually you want to generate such element, so you can easily generate a square.
Nov
16
comment Checking both Quadratic residuosity and Jacobi symbol simultaneously and efficiently
You can only generate a element and test if its Jacobi symbol is 1 or not.
Nov
16
comment Checking both Quadratic residuosity and Jacobi symbol simultaneously and efficiently
So you cannot generate a such element $u$. The problem to distinguish between quadratic residues mod N and pseudo quadratic elements is infeasible for a large enough N.