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Jul
3
reviewed Leave Open Using password-based encryption as a hashing scheme
Jul
3
reviewed Leave Open I hashed my bag and in it I put… “Is there a hash for unordered items?”
Jul
3
comment Meaning of pseudocode “$(C, S):=$”
@user3042720: if that answers the question, could you accept it (and possibly upvote it)? Thanks!
Jul
3
answered Meaning of pseudocode “$(C, S):=$”
Jul
3
comment Working on subgroup of $\mathbb{Z}^*_p$ in practice
To emphesize Henrick's point, different cryptosystems have different answers; in DH, we do want to stick to the subgroup; for SRP, we have to work with elements in the entire group
Jul
3
comment Is format preserving encryption suitable for use with words or names?
@erotavlas: Typically, FPE functions deal with base 2 numbers (or, more generally, base $2^k$). So, what I would do is convert from base 52 into base 2, pass that base 2 number to the FPE function, and then take the base 2 number it gives you and convert it base into base 52.
Jul
3
comment The encryption scheme is secure?
And how do you decrypt it? Or, is how $k$ is generated also part of the key?
Jul
3
comment Is format preserving encryption suitable for use with words or names?
@erotavlas: integers are not inherently in particular base; they can be represented in any base. And yes, you can represent any integer in base 10, if you want; however I would question the utility of doing so in this case.
Jul
2
revised One-one correspondance complete function
added 14 characters in body
Jul
1
revised One-one correspondance complete function
Tried to be less obscure
Jul
1
comment How often does RSA-OAEP have a leading zero?
If your vendor is unwilling to describe precisely what their crypto is doing, that is a strong indication to move to another vendor who is more transparent. The details on how to do strong crypto are not trade secrets; if they're hiding something, the likelihood is that they're hiding how bad their implementation actually is.
Jul
1
awarded  Nice Answer
Jun
29
reviewed Leave Open Bouncy Castle and Salsa 20
Jun
29
reviewed Leave Open Simplicity and precision in cryptography papers
Jun
29
reviewed No Action Needed ElGamal scheme attack when one message is known and ciphertexts are intercepted
Jun
29
reviewed No Action Needed Source for PKCS#11 Header Files
Jun
29
reviewed No Action Needed Double the key in block cipher - which approach is better?
Jun
29
reviewed No Action Needed Extracting a WinRAR password
Jun
29
comment Ideas for non duplicate cryptographically secure numbers
How large do the numbers need to be (in terms of bits)? They need to be at least 36 bits (so that there are at least 50 billion distinct possibilities)
Jun
29
comment What happens if no final subtraction is done in Montgomery multiplication?
Stupid question: why are you using Montgomery Multiplication for $2^{255}-19$ in the first place? The reason we do Montgomery Multiplication is to make the modulo operation easier; however with $N=2^{255}-19$, it's already awfully easy, as $a \cdot 2^{255} + b \equiv a \cdot 19 + b \pmod{2^{255}-19}$