ITC == Introduction To Cryptography

Some notes about the Homework #2

1. Generator

(a) Generator

(b) Diffie-Hellman Key Exange Protocol

• allows two parties to agree a secret key over an insecure channel without having met before.
• Its security is based on the discrete logarithm problem in a finite abelian group G.
  
  

(c) Man-in-the-Middle attack

(d) ElGamal cryptosystem

Modular multiplicative inverse

2. Euler’s Theorem is the extension of Fermat’s Theorem.

(a) Euler’s totient function

(b) Euler’s Theorem

(c) the last 3 digits of 8^803

8^{803}  \mod 1000 \equiv 8 \times 64^{400+1} \mod 1000 \equiv 8 \times 64 \equiv 512  

3.

multiplicative inverse

finite field

4. RSA

p, q, e, n, d

use Extended Euclidean algorithm

5. system of equations

Still don't get it...