meta user
network profile
| bio | website | |
|---|---|---|
| location | ||
| age | ||
| visits | member for | 1 year, 9 months |
| seen | 1 hour ago | |
| stats | profile views | 105 |
|
Apr 9 |
answered | What is the difference between CBC and GCM mode? |
|
Apr 8 |
comment |
CPA distinguisher for matrix multiplication in GF(256) with randomized padding @HenrickHellström: not a problem; as I said, Ilmari did give an answer (and I believe that it is in fact the best possible answer, that it, the minimum number of queries possible) to your original question. |
|
Apr 8 |
answered | CPA distinguisher for matrix multiplication in GF(256) with randomized padding |
|
Apr 6 |
comment |
Predicting PRNG given some of its previous output @SamerMeggaly: well, because $0 \le x_0 < p$, then we know that $0 \le 2*x_0 + 5 < 3p$, and so doing the $\bmod$ reduction will cut out between 0 and 2 multiples of p (and similarly on the y side). As for step two, we start by iterating through the various possibilities of bit 0 of p and bit 0 of $x_0$, and once we've determined settings that works, we start on bit 1 of both, and work our ways up until we've recovered the entire value (or decided that the particular $k_x, k_y$ values weren't the right ones) |
|
Apr 6 |
answered | Twofish key length |
|
Apr 6 |
answered | Predicting PRNG given some of its previous output |
|
Apr 5 |
reviewed | Approve suggested edit on Trouble with diffie-hellman groups |
|
Apr 5 |
reviewed | Approve suggested edit on Sites to find crypto intermediate values |
|
Apr 5 |
awarded | Fanatic |
|
Apr 4 |
comment |
Can you make a hash out of a stream cipher? Well, that is certainly a construction; however, you haven't shown that it is a secure construction. For example, Luby-Rackoff generates a PRF that is secure using the standard block cipher assumptions (that the key is secret and related key attacks do not apply); the Davies-Meyer construction assumes that we have an ideal block cipher (that the output is essentially a random function of the cipher and the plaintext). Does the Luby-Rackoff construction also provide the additional properties that Davies-Meyer requires? I wouldn't assume that. |
|
Apr 4 |
answered | Symmetric vs. Asymmetric cryptographic approaches to data security |
|
Apr 4 |
reviewed | Approve suggested edit on Symmetric vs. Asymmetric cryptographic approaches to data security |
|
Apr 4 |
comment |
ECC algorithm pollard's $\rho$ complexity @VineetMenon: It's generally well understood that for algorithms that take a single integer parameter, the complexity of the function is generally expressed as a function of the size of that integer in bits. |
|
Apr 3 |
comment |
Cryptographic security of PHP mt_rand() function using Mersenne Twister algo @owlstead: Do you have a link to the stackoverflow question? On the other hand, if you're just giving the output of MT to a hash function, that'd probably be safe (if a bit slow). On the other hand, just hashing the value of a counter is also practically speaking safe (and large counters both have long cycle times, and are even faster to update than MT). As for "provability", that's generally in reference to some cryptographical assumption (e.g. factoring is hard); is "you can't find preimages to SHA-512 given related plaintexts" an acceptable assumption? |
|
Apr 3 |
answered | ECC algorithm pollard's $\rho$ complexity |
|
Apr 2 |
answered | Trouble with diffie-hellman groups |
|
Apr 1 |
answered | How does one attack a two-time pad (i.e. one time pad with key reuse)? |
|
Mar 31 |
answered | Cryptographic security of PHP mt_rand() function using Mersenne Twister algo |
|
Mar 30 |
revised |
RC4 : Keystream reconstruction? added 177 characters in body |
|
Mar 30 |
answered | RC4 : Keystream reconstruction? |
