A theoretical introduction to cryptography. Subjects include private key cryptosystems, public key cryptosystems, digital signatures, secret sharing schemes, and the necessary mathematical background. Three lecture hours a week for one semester. Prerequisite: The following coursework with a grade of at least C-: Computer Science 429 (or 310) or 429H (310H); 331 (or 357), 331H (or 357H), 341, or 341H; and credit with a grade of at least C- or registration for: Mathematics 340L, 341, or Statistics and Data Sciences 329C (or Statistics and Scientific Computation 329C).