| # | Date | Topics | Reading | Handouts | Homework |
|---|---|---|---|---|---|
| 1 | F 9/11 | Introduction | Singh Ch 1, Pincock Ch. 1, Barr p. 1-4 | General information about the course | - |
| 2 | M 9/14 | Caesar cipher, letter frequency distribution, letter-number correspondence | Barr 2.1 | Bar graph of frequencies, Letter-number correspondence | - |
| 3 | W 9/16 | Modular arithmetic | Barr p. 59--63 | - | HW 1: Barr p.66: 1, 2, 3, 4, 6, 11, 14, 15. (due F 9/18) |
| 4 | F 9/18 | Multiplication | Barr p.69--76 | - | - |
| 5 | M 9/21 | Decrypting a multiplicative cipher | Barr p. 76--80 | - | HW 2: p. 80: 1, 2, 3abc, 4, 7, 8 (due Fri 9/25) |
| 6 | W 9/23 | (con't) | - | - | - |
| 7 | F 9/25 | Substitution ciphers | Barr 2.3 | - | Cipher "ETNAN XFWN LYK Y..." You can do this together with some others if you want. It's not necessary to fully complete the deciphering of this message but you should work on it. Please hand it in on Tuesday 9/29 and explain (briefly) what you have tried to do. (This is HW #3) |
| 8 | M 9/28 | Transposition ciphers | Barr 2.4 | Civil war ciphers (from Kahn). Also see posting on ella | HW 4: p. 105: 1, 2, 4, 5 (due F 10/2). Note that the answer to #1 is in the back of the book but please work it out rather than just copying the answer. |
| 9 | W 9/30 | Keyword transposition ciphers | - | In class exercise (get copies on my bulletin board) | Look on Ella to find a new version of problem #2 |
| 10 | F 10/2 | Vigenere cipher: encode, decode | Barr 2.5 | Vigenere square | Practice problems for class on Monday: p. 118 1a, 2a (do not hand in) |
| 11 | M 10/5 | The Kasiski test | see the syllabus | handout "IZGSV PFL..." for practice | Quiz 1 |
| 12 | W 10/7 | Find keyword of Vigenere cipher if know its length | Barr p. 111f. | handout "ANETJ..." for practice | - |
| 13 | F 10/9 | Atbash, Alberti ciphers | (see syllabus) | - | - |
| 14 | W 10/14 | Permutations and combinations | Barr 2.6 | paper clips | - |
| 15 | F 10/16 | Test I | - | - | HW 5 (due Tu 10/20): p. 33: 7,8. (Note: Capital letters indicate when and where to change the pointer k. Also "vv" stands for "w". |
| - | - | - | - | - | HW 6: (due W 10/21): p. 130: 1ab, 2ab, 3, 4, 5a, 6a. |
| - | - | - | - | - | HW 7: (due Th 10/22): p. 118: 1a, 2a, 3ab, 4, 6. |
| - | - | - | - | - | HW 8: (due F 10/23): p. 118: 5. (If you want you can do this problem together with one or two other people. Submit one paper with all your names on it.) |
| 16 | Mon 10/19 | Combinations; probability | Barr 2.6 | - | - |
| 17 | W 10/21 | Introduction to Friedman's IC | Barr 2.7 | - | Practice problems for Friday (see Ella) |
| 18 | F 10/23 | Index of coincidence (con't) | - | - | HW 9 (due Weds 10/28): p. 131: 8; p. 141: 1ab, 2, 3, 4. |
| 19 | M 10/26 | Binary numbers; ASCII | Barr 3.1 (p. 178-179) for the binary numbers; see wikipedia for ASCII | - | HW 10 (due 11/3): p. 185: 1, 4, 5 (In problem 5 ignore the first digit in each binary number) |
| - | - | LFSR: introduction | [Barr 3.4] | - | - |
| 20 | W 10/28 | LFSR (con't) | - | - | - |
| 21 | F 10/30 | Using the output from a LFSR to do a binary Vigenere cipher | - | - | - |
| - | - | - | - | - | Quiz II (on permutations and combinations) |
| 22 | M 11/2 | Cryptanalysis of the above. | - | ASCII table | HW 11 (on LFSR; due 11/6) |
| 23 | W 11/4 | Introduction to the Enigma | Singh 127-142, Pincock p. 102-103 | - | - |
| 24 | F 11/6 | (con't). Demonstration of two Enigma simulators (see Ella site for more info); an original page of instructions (see Ella); Calculation of the total number of settings. | - | - | HW 12 (on ella; do either the DR or the AC version, your choice). Due 11/11. |
| 26 | M 11/9 | Cracking the Enigma | Barr ch. 4; Pincock 98-117 | - | "The bombes" |
| - | - | The Playfair cipher | (see the syllabus) | - | - |
| 27 | W 11/11 | Public key ciphers: The knapsack problem | (see the syllabus) | Worksheet on knapsacks (see ella) | - |
| 28 | F 11/13 | (con't) | - | Worksheet II on the knapsack cipher | HW 13: p. 272: 1, 2, 3, 4 (here w^(-1) = 881 mod p), 6, 7. (due 11/19) |
| 29 | M 11/16 | Movie: Cryptology in WW II | - | - | - |
| 30 | W 11/18 | Review of topics for test. Introduction to prime numbers and the RSA cipher | Barr 4.1 | - | - |
| - | F 11/20 | Test II | - | - | - |