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reviewed No Action Needed Secure way to derive separate encryption and MAC keys from a single master key?
Oct
22
comment What is the use of Mersenne Primes in cryptography
Two issues with the cited random number paper: a) it doesn't actually talk about Mersenne primes, but numbers of a related form, and b) I don't believe that the random number generators cited are actually cryptographical (that is, indistinguishable from a truly random bit generator).
Oct
22
revised What is the use of Mersenne Primes in cryptography
deleted 5 characters in body
Oct
22
answered What is the use of Mersenne Primes in cryptography
Oct
21
reviewed Close counting points not on elliptic curve
Oct
21
reviewed Close Crypto Libraries with Pairing Based Functions for Academic and Educational Use?
Oct
21
reviewed Leave Open What's algorithm encryption ?Twofish or AES
Oct
21
comment To prove $r_2$ is a uniformly at random value in $Z_n$, where $r_2=r_1 . m$
By computation while they are at the server, you mean the RSA public or private operations? If so, well, what you're doing is known as RSA Blinding; it's a well known technique to allow someone to do the RSA operations without leaking what they're operating on. It's known to be safe.
Oct
21
comment To prove $r_2$ is a uniformly at random value in $Z_n$, where $r_2=r_1 . m$
The answer to that would depend on what you mean by 'security'. You may find it helpful to write down exactly what you mean by that; what security properties are you expecting?
Oct
21
comment To prove $r_2$ is a uniformly at random value in $Z_n$, where $r_2=r_1 . m$
@user153465: the answer to question 1 is "no"; if $m$ is an arbitrary value, consider the case that $m=0$; obviously in that case, $r_2$ is not a uniform random value. For the answer to question 1 to be "yes", we need to put restrictions on the distribution $m$ is chosen from (specifically, that probabilities that $m$ is a multiple of $p$, $q$ and $pq$ must be $1/p$, $1/q$ and $1/pq$)
Oct
20
reviewed Close Protection of Elliptic Curve Implementations against side-channel attacks
Oct
20
answered Does a stream cipher require a KDF when it's key is variable length?
Oct
19
comment Does the transposition cipher have a network application?
@jake.toString: I suspect it'd be unlikely that anyone would write "we never use transposition ciphers in network applications" unless someone specifically asked.
Oct
19
reviewed Close problem with “one time pad”
Oct
19
comment problem with “one time pad”
possible duplicate of How does one attack a two-time pad (i.e. one time pad with key reuse)?
Oct
19
reviewed Close Weak key schedule IDEA
Oct
19
reviewed Leave Open I need to know number of encryption/decryption operations?
Oct
19
comment Does the transposition cipher have a network application?
I'm not sure how to answer this other than saying that I've never seen a transposition cipher within a network security protocol, and I have a good deal of experience in that area. It's not clear to me why anyone would choose to use a transposition cipher as opposed to one we are confident is semantically secure.
Oct
15
awarded  Nice Answer
Oct
10
answered How do RSA and ElGamal key sizes compare?