Skip to main content

All Questions

1 vote
1 answer
101 views

distribution of square roots of unity $mod n$ | Factoring with inverse pair

I am writing a proof related to the RSA cryptosystem, specifically showing that given an inverse pair $d, c$ under multiplication mod $\phi(N)$, where $$ dc \equiv 1 \pmod{\phi(N)}, $$ there exists a ...
FieldHouser's user avatar
2 votes
0 answers
81 views

Finding primitive roots including negative sign

I commonly run into the following question such that if $p$ and $q=4p+1$ are both odd primes prove that $2$ is primitve root modulo q . However , i could not prove it for other number that are given ...
user avatar
0 votes
0 answers
73 views

proving no primitive roots exist modulo $2^n$ for n $\geq$ 3

Ive been asked to prove by induction that no primitive roots exist modulo $2^n$ for n $\geq$ 3. I have proven true for base case $n=3$, and assumed to be true for $n$. I'm now stuck at this point: $${...
georgielee2000's user avatar
1 vote
2 answers
255 views

Confusion about the choice of primitive root/multiplicative generator in Diffie-Hellman Key Exchange.

I was reading "Jeffrey Hoffstein, Jill Pipher, Joseph H. Silverman, An Introduction to Mathematical Cryptography, Second Edition". I understand the basic Diffie-Hellman Key Exchange. Though, I was ...
scribe's user avatar
  • 524
3 votes
0 answers
105 views

solutions of gold APN functions using trace function

The Gold APN is defined as $F(x)=x^{2^{k}+1}$ in $GF(2^n)$, where $\gcd(k,n)=1$. The differential uniformity computed using $F(x)=F(x+a)=b$ as following: $x^{2^{k}+1} + (x+a)^{2^{k}+1}=b$ $x^{2^{k}+...
hardyrama's user avatar
  • 215
0 votes
1 answer
245 views

Exponential modular arithmetic for Diffie-Hellman

I've been playing around with some finite fields to test how rapid brute-force is when solving discrete logarithm problems occurring in DH methods. Working in $\mathbb{F}_{101}$, pick a private key $\...
PLY's user avatar
  • 241
0 votes
0 answers
133 views

Existence of solutions to DLP and Primitive roots mod $p$

Discrete log problem - finding $x \ge 0$ for prime $p$ , generator $g>0$ and $h>0$ such that: $$g^x \cong h \pmod{p}$$ Define $G$ as the group generated by all values of $g^x \pmod{p}$. Eg $G=$...
unseen_rider's user avatar
1 vote
0 answers
54 views

Question related to N-th cyclotomic polynomial, principal N-th root of unity and residue class of X

I am struggling to understand a couple of statements in a cryptography-related paper. I think I lack some maths background. Can you help me understand it ? Here are the statements: We consider the ...
crypto7's user avatar
  • 11
1 vote
1 answer
1k views

Proof of $\log_{a}(b_1b_2) = \log_{a}(b_1) + \log_{a}(b_2) $ for discrete logarithm?

If you have that $a$ is a primitive root mod $p$. How can you prove this discrete logarithm property? $\log_{a}(b_1b_2) = \log_{a}(b_1) + \log_{a}(b_2) \pmod{p-1}$ I see the proof for the regular ...
omega's user avatar
  • 761
1 vote
1 answer
815 views

Diffie–Hellman key exchange

Today I have learned about primitive roots, as part of my study about Diffie-Hellman, This is the formula: G(generator), P(prime), A(side A), B(side B) A = G^A MOD P B = G^B MOD P AS is a secret key ...
Aviel Fedida's user avatar
120 votes
5 answers
181k views

Finding a primitive root of a prime number

How would you find a primitive root of a prime number such as 761? How do you pick the primitive roots to test? Randomly? Thanks
user avatar