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Jan
15
comment Nonces being used in SSL and MAC to prevent replay attacks
What do you mean by MAC? Is that a Message Authentication Code (which is used in SSL)?
Jan
14
answered TimeStamp in Cache-time attacks on AES
Jan
14
revised How bad would it be to reuse the random blinding factor in a scheme like Paillier?
Explicitly added answer to question
Jan
14
answered How bad would it be to reuse the random blinding factor in a scheme like Paillier?
Jan
14
comment Factors of RSA modulus
@fgrieu: actually, the real figure is 1/2, not 3/4 (I've corrected my answer). As for a simple proof, well, one won't fit on this response, however here's how it works: if we look at the behavior of $(m^\lambda)^{2^i}) \pmod p$, we see that it has a probability 0.5 of turning into 1 at step $j$ (where $j$ is such that $(p-1)/j$ is odd), and a probability 0.5 of turning into 1 at some earlier step; and similarly with $q$. Now, $m$ will reveal a factorization if $p$ and $q$ turn into 1 on different steps.
Jan
14
revised Factors of RSA modulus
edited body
Jan
13
answered Factors of RSA modulus
Jan
13
comment Comparison among algorithm based on key length
Minor correction about RSA: actually, values of $e$ (and $d$) which do not work need not be rare; for one, even values never work (because $\phi(n)$ is always even). In addition, if $\phi(n)$ is a multiple of 3 (which will happen with probability 3/4 if $p$ and $q$ were not chosen with mod 3 in mind), then any $e$ which is a multiple of 3 will also not work. If $p$ and $q$ are chosen such that $p-1$ and $q-1$ has no small odd factors, then most odd values of $e$ and $d$ will work; however we generally don't use such criteria when selecting $p$, $q$
Jan
13
comment Can you help me with this Random Number Generator function?
@tylo: actually, it does make sense. One of the possible ways of doing the output is provide a function that, given $i$, gives you the $i$th member of the permutation. However, Rahul has never said how we wants the output represented, so we're just guessing...
Jan
13
reviewed No Action Needed Epsilon Differential Privacy when using a random function
Jan
13
reviewed Looks OK Comparison among algorithm based on key length
Jan
13
reviewed Looks OK Problem with implementing DES in python
Jan
12
reviewed Leave Closed Is there a client-side program to cryptography a HTML page and decode if correct password is writen?
Jan
12
reviewed Reviewed P = NP and current cryptographic systems
Jan
12
comment P = NP and current cryptographic systems
Link-only posts aren't very helpful if the link moves. It's generally recommended that you summarize what the link has to say within the answer.
Jan
12
reviewed No Action Needed Integrity protection in wireless sensor networks
Jan
12
reviewed No Action Needed private keys for multiple devices
Jan
12
comment Question about the Theta step of Keccak
If you asking about how to invert the Theta step, well, sorry but my results don't tell you that. They're nonconstructive; they show that no two inputs result in the identical outputs for (x=5,y=5,z=64), hence for any output, there must be a unique input -- but they don't give any clue how to find that unique input.
Jan
12
comment Random Galois fields
If you include the requirement that addition is implemented by bitwise xor, then all such representations have multiplications that can be implemented by a bitwise linear map of the two parameters, followed by a multiply within the $x^8+x^4+x^3+x+1$ representation, followed by another bitwise linear map (actually, the inverse of the first map). Hence, it doesn't appear that a random representation is any more 'nonaffine' than the standard one. How does inserting linear operations before/after the multiply make it less linear?
Jan
12
awarded  initialization-vector