Today

Motivation

Terminology

Our System Model

Cryptography (crypto for short)

Symmetric ciphers

Signatures and hashes

Data storage: Passwords

NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO. NEVER IMPLEMENT YOUR OWN CRYPTO.