●●●●● ●●●● ●●0 Outline ●●● ●●●● Overview of Cryptography Classical Encryption Techniques Substitution Transposition ● Block Ciphers DES AES COMP4690. HKBUCOMP4690, HKBU 2 Outline ⚫ Overview of Cryptography ⚫ Classical Encryption Techniques ⚫ Substitution ⚫ Transposition ⚫ Block Ciphers ⚫ DES ⚫ AES