Paul Garrett's Crypto and Number Theory Lecture Notes

Introduction to cryptology, number-theory, and algorithms. Protocols. Symmetric versus asymmetric systems. Stream, block ciphers. One-way functions, signatures. Key management. (Pseudo-) random number generation. Permutation groups. Primes, Euclidean algorithm. Finite fields. Quadratic reciprocity. Discrete logs, RSA. Pseudoprimes, rho method. Elliptic curve methods.