This lecture introduces the four basic security services and some of the terminology associated with computer security. It also introduces symmetric cryptography, both classical and modern, and the API available in JCE, the Java Cryptography Extension, to generate keys and cipher engines.

• The Basic Security Services
• Brute-Force versus Cryptanalysis
• Classical Ciphers and their attacks
• Substitution and Transposition
• Modern Symmetric Ciphers
• The Java API

• Examine the programs in the jce subdirectory of the Resource Directory.