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Nov
22
comment Real life systems that use concepts of crypto computing
Making this CW so that others can edit and add additional information more freely.
Nov
22
answered Real life systems that use concepts of crypto computing
Nov
21
comment Python. RSA common modulus attack problem
I am familiar with python and can give you a few pointers. First, with pow, pow supports a third parameter to compute modular exponentiation. So doing pow(a,b,n) computes, $a^b\bmod{n}$. For computing inverses, I typically use pycrypto (Crypto.Util.number.inverse).
Nov
20
comment Are all binary-additive stream ciphers reciprocal?
The inverse of XOR is XOR, so yes.
Nov
20
comment Is there a Javascript and Java implementation of a good CSPRNG
Why do they have to be the same algorithm? Could you run node.js on the server side? I think your question would be better off on a different site. This site is more about theoretical aspects of crypto. StackOverflow or IT Security could be better sites. If you want me to migrate the question, let me know.
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Trying to add/invite you. Are you the other person in the room?
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Let us continue this discussion in chat.
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Looking at Lemma 2, $r,s$ have degree $\beta$ where $\beta\geq\alpha$ where $\alpha$ is the degree of $f$ and $g$.
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Their Lemma 2 does specifically have that $degree(r)$ and $degree(s)$ $>$ $degree(f_1)$ (and $f_2$). Not sure if it can be extended to the case where $degree(r)=1$. Just checking, you do mean degree $1$ for $r$ and not $0$ (a random constant), right?
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Looking over that paper, they say that given $f*r + g*s$, where $f$ and $g$ are the polynomial representations of $S$ and $T$ respectively and $r$ and $s$ are random polynomials of degree $deg(f)$, the attacker learns no additional information about $S$ and $T$ than what can be deduced from $S\cap T$. Not sure how this directly translates to your problem.
Nov
20
answered To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
Nov
20
comment To prove $r \cdot f_1 +f_2 \cdot (s+1)$ is secure
One more question. Multiplying two polynomials increases the degree of the polynomial. Basically the degrees add. You aren't doing any dimensionality reduction step (like we typically see with shamir based MPC), are you?
Nov
18
comment Interactive assumptions not falsifiable?
Can you give us more context? Did you read this in a paper or book? A link to the material with relevant quotes pasted into the question would be very helpful.
Nov
17
comment what does rsaSha512Sign do?
What library is it?
Nov
17
comment Collision resistant hash functions
This isn't a question answering service. What have you tried? Where are you stuck?
Nov
17
awarded  Enlightened
Nov
17
awarded  Nice Answer
Nov
16
comment Decrypting A Cipher Text without knowing the key or plaintext
What research have you done? There is tons of material out there on breaking vigenere. I think there are even some good posts on this site.
Nov
14
comment How many of primitive point on the elliptic curve?
Related question on another site math.stackexchange.com/questions/455008/…
Nov
13
comment Perfectly secret cipher can leak about the key?
Let me make sure I understand, you pad a message with random data, then encrypt with OTP. Leak the key bits that encrypt the padding?