Diffie-Hellman Key Exchange and ElGamal Cryptosystem

This lecture covers the Diffie-Hellman key exchange protocol, explaining how it works in any group and its application in SSH2. It also delves into the ElGamal cryptosystem, a public key crypto system based on the Diffie-Hellman protocol, discussing its key generation, encryption, and decryption complexities. The lecture further explores the security aspects of these protocols, including the computational Diffie-Hellman problem and the key recovery problem. Additionally, it presents the Chinese Remainder Theorem and its applications in RSA, demonstrating how it can be used to speed up decryption processes and prove the correctness of RSA encryption and decryption operations.