CS 4363 -- Spring 2007 -- Lecture 1 Notes

CS 4363, Spring 2007
Lecture 1 Notes, 10 April 2007

Model for symmetric cryptosystem
One-time-pads
- Exclusive-or (same as addition mod 2)
- One-time-pad, bit version
- One-time-pad is perfect (unconditionally secure)
- Alpha version of one-time-pad, spies
Use of pseudo-random-number-generators
- Pseudo-random-number-generators (bit stream version)
- Outline of a cryptosystem based on a PRNG (RNG-based cryptosystem)
- Not necessarily secure
- Specific example (Encode.java, Process.java, GetNext.java)
Block ciphers
- Outline of a block cipher
- Can't have blocks too small
- Outline of DES
- History of DES, security parameters
- Cipher block chaining (CBC diagram)

Revision date: 2007-04-09. (Please use ISO 8601, the International Standard.)