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Jun
21
reviewed Approve Is there a malleable pubkey digital signature scheme?
Jun
21
reviewed Approve Hill cipher key space
Jun
21
reviewed Approve Unblind a RSA blinded signature
Jun
12
reviewed Approve How realistic is a dictionary attack on a secure remote password protocol (SRP) verifier?
May
29
reviewed Approve Encryption time in ECC
May
28
reviewed Approve Is the logic for how the enigma machine worked documented somewhere?
May
28
reviewed Approve how much trust can we place in protocol verifiers?
May
22
comment One-time pad, zero key and Shannon
By "using Shannon" you mean applying Shannon's theorem? Sure, you can define your key-generation algorithm to pick the all zero key with probability 0 and all others with probability $1/(|\mathcal{M}|-1)$. That's exactly your encryption scheme. Then apply the theorem which states that the scheme is perfectly secret if and only if two condition hold. One of those conditions is that every key is chosen with the same probability, which obviously does not hold.
May
22
comment One-time pad, zero key and Shannon
@CGFoX Well, we are talking about the OTP here (except that the all zero key is not allowed), so by definition, $\mathcal{M}=\mathcal{C}=\{0,1\}^n$. But even if they are some other sets. If the set of keys has an element less that the messages, then for any ciphertext $c$, there exists at least one message $m$ that cannot possibly result in $c$ no matter which key is chosen.
May
21
reviewed Reject Shamir Secret sharing - Can share generator keep x values secret?
May
21
reviewed Reject Shamir Secret sharing - Can share generator keep x values secret?
May
21
revised One-time pad, zero key and Shannon
Added a bit more explanation, why this is a valid argument.
May
21
answered One-time pad, zero key and Shannon
May
21
comment Which concrete applications benefit from Oblivious RAM constructions?
@e-sushi I don't quite get what your comment is trying to convey. He is NOT asking about attacks on ORAM (this is indeed a much used abbreviation). He is asking about the attacks on non oblivious encrypted data-structures that are the motivation to develop ORAM construction (be that Hash based or whatever)
May
21
reviewed Close encryption and decryption time for RSA-crt in java?
May
21
comment Prefix property for variable length pseudo-random generators
$m_0$ and $m_1$ certainly still have to have the same length. Check Definition 3.8. With messages of different length, the security definition becomes meaningless.
May
15
reviewed Reject Is it possible to construct a secure block cipher of size $2n$ given a secure block cipher of size $n$?
May
11
comment The advantages of Merkle Signature and One time Signature
Of course it does: Only a single message can ever be securely signed under the public key of an OTS. In contrast, many messages can be signed under the public key of the Merkle scheme without compromising security.
May
9
reviewed Approve Cryptographically secure keyed rolling hash function
May
6
comment Is G is a secure PRG?
You should specify what F is (I assume a pseudorandom function) and where k comes from.