Chapter 1. The unix password Based authentication system. Chapter 2. Symmetric encryption in .NET. Chapter 3. Hash functions and MAC codes in .NET. Chapter 4. The RSA public-key cryptosystem in .NET. Chapter 5. The DSA signature algorithm in .NET. Chapter 6. Computational problems behind public-key cryptosystems, BigIntegers in Java. Chapter 7. Cryptography in Java: symmetric and asymmetric encryptions, password based key-derivations.