Lecture 7: AES & Hash Functions (10 Feb)

In today's lecture, Dr. Gunes ,first, went over the RSA. Then, we began discussing Advanced Encryption Standard(AES) in more detail. He gave brief information about how the first AES is implemented and why DES was not sufficient. Then, he explained the architecture of AES and its requirements. In AES, each round consists of four main operations: byte substitution, shift row, mix columns and add round key. And the number of rounds needed is different for each bit length. He explained these four main steps with examples. Then, he compared DES and AES. One interesting thing was that DES still widely used around the world to protect sensitive online applications. Finally, he mentioned about cryptographic hash functions: Message Digest Functions(MDFs) and Message Authentication Codes(MACs).