| # | Date | Topic | Homework | |
|---|---|---|---|---|
| 1 | M 1/30 | Introduction | Read Ch. 1 of Code Book | |
| 2 | W 2/1 | Shift ciphers: their encoding and decoding | Barr p. 66 (2.1) 1 (due 2/3) | |
| 3 | F 2/3 | Discuss methods for cryptanalysis of shift cipher. Associate letters with numbers mod 26. Modular arithmetic (Barr 2.1: 59-63) | HW 1: Barr p. 66 (2.1): 2 (due 2/6) | |
| 4 | M 2/6 | Modular arithmetic: addition, multiplication, inverses (Barr p. 73-76) | HW 2: Barr p. 80: 1, 2 (due 2/8) | |
| 5 | W 2/8 | Decimation ciphers (Barr 2.2) | Singh Cipher Stage 2, p. 354 (due 2/13) | |
| 6 | F 2/10 | Affine ciphers (2.2) | - | |
| 7 | M 2/13 | Transposition ciphers (2.4) | HW 3: p. 80: 3ab, 4ab, 5ab, 7 (due 2/15) | |
| 8 | W 2/15 | Substitution ciphers (2.3) | HW 4: Finish "Etnan ...". Optional: Singh Stage 1 (or some of it) | |
| - | - | - | HW 5: p. 105 (2.4): 2, 4, 5. p. 118: 1a, 2a (due 2/20) | |
| 9 | F 2/17 | Vigenere cipher (2.5): encipher, decipher, cryptanalysis when keyword length is known | - | |
| 10 | M 2/20 | - | Finish handout "AWYVPQ..." | |
| 11 | W 2/22 | Quiz 1 (on material in 2.1) | - | |
| - | - | Kasiski test | HW 6: p. 141: 8 (due 2/24) | |
| 12 | F 2/24 | [no class] | - | |
| 13 | M 2/27 | Quiz 2 (on material through 2.2) | - | |
| 14 | W 3/1 | - | Practice problems for test (do not hand in): p. 80: 3c, 5c, 6 / p. 106: 5 / p. 118: 2b | |
| 15 | F 3/3 | Test I (on material through 2.5, also Singh ch. 1) | - | |
| 16 | M 3/6 | Two methods to solve Vigenere cipher when keyword length is known (Barr p. 112f, Koblitz) | - | |
| - | - | Permutations (2.6) | HW 7: p. 118: 6, p. 130: 1ab (due 3/8) | |
| 17 | W 3/8 | Combinations (2.6), Index of coincidence (2.7) | HW 8 (2.6): p. 130: 2ab, 3, 4 | |
| 18 | F 3/10 | More on index of coincidence | HW 9 (2.7): p. 141: 1ab, 2, 3 (due 3/17) | |
| - | - | Polybius cipher, homophonic ciphers (handout: Kahn p. 107) | - | |
| 19 | M 3/13 | [hand back tests] | - | |
| 20 | W 3/15 | Playfair cipher | HW 10: p. 36: 16, 17 (due 4/31) | |
| - | F 3/17 | [no class] | - | |
| 22 | M 3/27 | Introduction to the Enigma (handout of pictures, code book) | Read Singh p. 127-142 | |
| 23 | W 3/29 | A detailed reference for the Enigma and a good Enigma simulator | - | |
| 24 | F 3/31 | The Enigma: the number of possible keys | Read Singh Ch 4. HW 11: see below (due 4/5) | |
| - | - | Prime numbers (Barr 4.1) | HW 12: p. 260: 1, 2, 4, 5, 6ab (due 4/7) | |
| - | - | - | HW 17: Cryptograms in foreign languages. Use Letter frequencies in foreign languages. (due 4/21) | |
| 25 | M 4/3 | Ingredients of the RSA cipher: primes, factoring, gcd, modular exponentiation, Fermat's little theorem (Barr p. 277) | HW 13: p. 94: 7 (due 4/7) | |
| 26 | W 4/5 | - | - | |
| 27 | F 4/7 | - | - | |
| 28 | M 4/10 | Demo RSA using Maple | - | |
| - | - | Numbers in binary (Barr 3.1) | HW 14: p. 185: 1ab, 2ab, 4 (due 4/14) | |
| 29 | W 4/12 | More on binary numbers | - | |
| - | - | Knapsack ciphers (Barr 4.2) | - | |
| 30 | F 4/14 | - | HW 15: RSA homework | |
| - | - | - | HW 16: Enigma message | |
| 31 | M 4/17 | Review for test | - | |
| - | - | Knapsack ciphers (con't) | - | |
| 32 | W 4/19 | Test II (note change in date) | - | |
| 33 | F 4/21 | The M209-B (guest speaker Prof. Curtis Smith) | - | |
| 34 | M 4/24 | Knapsack ciphers (con't) | HW 18: p. 272: 1abc, 2, 3abd, 4, 6 (due 4/28) | |
| - | - | - | HW 19: p. 272: 7 (due 5/1) For this exercise you will need the inverse of 91 mod 8017; this is 881. | |
| 35 | W 4/26 | Digital signatures (Barr 4.6), Hashing (Barr 3.6) | - | |
| 36 | F 4/28 | [hand back tests] | - | |
| 37 | M 5/1 | Movie "Spies" | - | |
| 38 | W 5/3 | ADFGVX cipher (Barr p. 21, Singh p. 374) | HW 20: p. 36: 20 (due 5/8) | |
| - | - | Hashing (Barr 3.6) | HW 22: p. 241: 1, 2 (due 5/9) | |
| - | - | DES (Barr p. 323) ( An online DES) | - | |
| 39 | F 5/5 | - | HW 21: Digital signatures | |
| - | - | - | Reading: Sharing the Burden: Women in Cyrptology during WWII | - |
| 40 | M 5/8 | Cryptography in the present day: passwords, login, steganography and more | Final examination |