1) Introduction, principle's of well-ordering and induction. 2) divisibility 3) prime numbers 4) greatest common divisor 5) the Euclidean algorithm 6) fundamental theorem of arithmetic 7) factorization methods 8) linear diophantine equations 9) linear diophantine equations 10) MIDTERM 1 11) congruences 12) linear congruences 13) chinese remainder theorem 16) Fermat's little theorem 17) primality testing 18) Euler's theorem 19) Euler-Phi function 20) M"obius Inversion 21) application (hashing function) 22) application (check digits) 23) MIDTERM 2 24) application (RSA) 25) application (RSA) 26) application (RSA)