- Introduction to Cryptography
- Simple Ciphers

- Defining functions with proc; Local and global variables
- Caesar cipher redux
- Improved Caesar-like ciphers

- Reading and Writing from a file
- Affine enciphering

- Enciphering matrices
- Treating text as vectors
- Affine encoding with matrices
- A Known-plaintext attack on an affine matrix cipher

- Modern cryptography

- Some Number Theory
- The greatest common divisor and the Euclidean algorithm
- The Chinese Remainder Theorem
- Powers modulo n
- The Euler -function and Euler's Theorem

- The RSA Public key cryptosystem

- RSA encoding a file

2002-08-29