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Dec
9
accepted Why is OCB-AES mode not becoming a standard for authenticated encryption?
Dec
9
asked Why is OCB-AES mode not becoming a standard for authenticated encryption?
Dec
9
revised Public key cryptography - public key encrypts and cannot decrypt?
deleted 12 characters in body
Dec
7
answered Public key cryptography - public key encrypts and cannot decrypt?
Dec
5
comment How to prove membership of a list without disclosing the list members?
Yes you are correct. Another possibility would be to use modified bloom filters to support the security you want. This comes with a cost of false positive replies by the bloom filter for membership queries. fkerschbaum.org/dbsec11.pdf
Dec
3
answered How to prove membership of a list without disclosing the list members?
Nov
27
answered Is the AES encryption scheme CPA secure?
Nov
26
awarded  Yearling
Nov
26
comment Looking for examples for “proof by reduction”
I may run the danger to be a bit out of topic but this is an interesting approach on rigorous proofs by reductions usually employed by cryptographers. It criticizes the too much effort on proofs by reductions which sometimes doesn't take into account all the attacker's window and consequently "tends to kick dust to eyes"
Nov
23
comment Mapping between subgroups and the integers
Can you also explain why since $q$ is a big prime, it is odd, therefore $p = 3 \mod 4$ and that implies that $x$ is a quadratic residue?
Nov
19
accepted Does a break in a collision resistance property of a hash function by definition implies an attack at the first pre-image attack?
Nov
19
comment Does a break in a collision resistance property of a hash function by definition implies an attack at the first pre-image attack?
@CodesInChaos break collision resistance means to find two messages m1,m2 which are not equal s.t: h(m1)=h(m2). Break first preimage resistance means break the one-wayness, recover m1 from h(m1)
Nov
19
asked Does a break in a collision resistance property of a hash function by definition implies an attack at the first pre-image attack?
Nov
19
comment Using CBC with a fixed IV and a random first plaintext block
That's why it is a comment and not an answer. Since you are using a source of randomness i can't see why not use it to produce the initial IV. In terms of efficiency this will increase linear the size of the ciphertext compared with the standard way
Nov
19
comment Using CBC with a fixed IV and a random first plaintext block
Why to do that?Is like CTR mode with 1 counting step, but in CTR the IV+the counter are encrypted with AES and this is XORed with the plaintext. If the IV is not random it must be unique, that's why we use a counter
Nov
19
comment Is it safer to encrypt twice with RSA?
@D.W. Is there a quantitative assessment in how large this partial plaintext recovering should be in order to be conjectured as CPA?
Nov
18
answered Relative merits of AES ECB and CBC modes for securing data at rest
Nov
17
accepted Why does OAEP have 2 rounds with 2 random oracles?
Nov
16
comment Is it safer to encrypt twice with RSA?
Does the fact that a tiny amount of information is discovered for the plaintext from the ciphertext violates the IND-CPA security? I am wondering as IND-CPA refers to fully recover the plaintext
Nov
15
asked Why does OAEP have 2 rounds with 2 random oracles?