Week 4

02/12/2008 (Tu, Lecture 6): We finished our discussion on mathematical background
needed for public-key cryptography. We started discussing the public-key crypto-system
called RSA. The proof that RSA works uses the Chinese Remainder Theorem (CRT).

02/14/2008 (Th, Lecture 7): We discussed the public-key crypto-system by Elgamal.
The security of this crypto-system depends on the hardness of the discrete-log problem.
We also covered the Diffie-Hellman key exchange protocol and discussed a man-in-the-middle
(MITM) attack on this protocol. We also briefly discussed the concept of zero-knowledge
proofs (ZKP).