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Jun
4
comment What's the inverse function of this decryption function?
What makes you think that there exists an inverse?
Jun
4
answered Why is a Feistel network bijective?
Jun
3
answered Is it OK to substitute a PRF for a random oracle?
Jun
3
reviewed No Action Needed Brute Force on Key
Jun
3
reviewed Reviewed Is it OK to use a hash of the key as nonce for AES GCM?
Jun
3
comment Is it OK to use a hash of the key as nonce for AES GCM?
Do you mean AES GCM mode?
Jun
3
revised How is information disclosed by modular multiplication?
English...
Jun
3
answered How is information disclosed by modular multiplication?
Jun
3
reviewed No Action Needed Anyone familiar with domain of hash functions in bilinear pairing based system?
Jun
3
reviewed No Action Needed Sending the next one-time pad key in this one-time pad message?
Jun
2
reviewed Reviewed Using ECDSA keys for encryption
Jun
2
comment Using ECDSA keys for encryption
ECIES is a public key encryption system; one side has a public key and uses that to encrypt, the other side has the private key and that allows him to decrypt.
Jun
2
reviewed Close AES-CTR in BouncyCastle with string key, without IV or salt
Jun
2
comment Is $(a,g^{ab})$ computationally indistinguishable from $(a, g^c)$?
Correction: if q has no small factors, then they are statistically indistinguishable. For example, if $q = 2r$ for large prime $r$, it's not smooth; however is $a$ is even and $c$ is odd, $g^{ab}$ and $g^c$ can be distinguished.
Jun
2
comment Is it possible to make an encrypted text look like a sentence consists of random words?
@StevePeltz: actually, there's no need to restrict yourself to power-of-2 number of choices. It's certainly easier with the restriction; however the difficultly of handling the general case pales in comparison with the difficulty of the overall task.
Jun
2
comment Property of Multiplicative group of integers mod n
If the order of a value $g$ is $q$, then there be precisely $\phi(q)-1$ other values that also have order $q$. This is independent of what $p$ is (other than $q$ is necessarily a divisor of $p-1$). If your case, we have $q=11$, hence there are $\phi(11)-1 = 9$ other values (that is, other than 2) that have order 11 modulo 23.
Jun
2
comment Property of Multiplicative group of integers mod n
Again, in this case $4 \cdot 6 = 1 \pmod{23}$, that is, $4$ and $6$ are inverses of each other. Yes, except for $g = 1$ and $g=-1$, there will always be a second generator with the same order as the first. And, yes, this behavior happens only for exponents that are modulo -1 to the order of $g$
Jun
2
comment Property of Multiplicative group of integers mod n
Actually, this is true only if your two generators $g, h$ satisfy $g \cdot h = 1$, that is, they are inverses of each other. In that case, they'll have the same order, and both $g^{q-1} = h$ and $h^{q-1} = g$. This won't hold true if the two generators are in the same order (for example, $g=2$ and $h=4$), but $g \cdot h \ne 1$
Jun
2
comment Is it possible to make an encrypted text look like a sentence consists of random words?
Might I ask why you want to do this? If you're looking to do Stegangraphy, well, that's a lot harder than just generating text with valid English syntax.
Jun
1
comment How was the MDS matrix used in AES chosen?
One other thing to note is that this choice of the matrix makes the inverse matrix not too horrid to compute as well.