Applied Cryptography: Symmetric Encryption and Hash Functions

This lecture covers the fundamentals of applied cryptography, focusing on symmetric encryption and hash functions. Topics include the One Time Pad for perfect secrecy, stream ciphers for confidentiality, modes of operation like ECB and CBC, Message Authentication Codes for integrity, and the properties of hash functions. Practical scenarios are discussed, such as choosing encryption schemes for high-speed links and using commitment schemes to prevent tampering with values. The lecture emphasizes the importance of key management, confidentiality, integrity, and authentication in cryptographic protocols.