The arithmetic tag has no wiki summary.
5
votes
3answers
195 views
How to best obtain bit sequences from throwing normal dice?
Throwing normal dice, one can get sequences of digits in [0,5]. Which is the best procedure
in practice to transform such sequences into bit sequences desired?
3
votes
1answer
60 views
Chosen ciphertext insecurity in an ElGamal variant
I'm trying to prove something and if I can show that there is a simple way to calculate $(g^a \bmod p)^k$ if I know both $g^k \bmod p$ and $g^a \bmod p$, then (I think) it will help me prove it, but ...
2
votes
2answers
119 views
Timing attack on modular exponentiation
It is known that computing $a^x \bmod N$ takes $O(|x| + \mathrm{pop}(x))$ multiplications modulo $N$, where $|x|$ is the number of bits of $x$ and $\mathrm{pop}(x)$ is the number of $1$ bits (Hamming ...
2
votes
1answer
638 views
What exactly is addition modulo $2^{32}$ in cryptography?
EDIT: I've been confusing this the whole time. What I've been wanting to say this whole time is addition modulo $2^{32}$ not addition modulo 32 as the question originally said. Thanks for pointing ...
1
vote
1answer
65 views
ECC Point Multiplication of Product
I can calculate $Q = a\,b\,G$ in several ways:
$Q = a \, (b \, G)$ or $Q = b \, (a \, G)$. These give the same result, as expected.
But if I do $c = (a \, b) \bmod n$ where $a \, b$ is much greater ...
1
vote
1answer
173 views
Simple example for CP-ABE (Ciphertext policy attribute-based encryption)
I'm currently working on Ciphertext Policy Attribute-Based Encryption (CP-ABE). So far I'm only using it with a basic understanding how it actually works. Now I want to understand it a bit better, but ...
0
votes
0answers
82 views
computing inverses in truncated polynomial rings manually for NTRU encryption
Can someone explain how to find inverses in truncated polynomial rings manually (i.e. on pen and paper)?
As an example from the tutorial:
Example. Take $N=7$, $q=11$, $a=3+2X^2-3X^4+X^6$. The ...
