| # | Date | Topics | Handouts | Reading | Homework |
|---|---|---|---|---|---|
| 1 | Th 9/20 | Using Excel to do affine ciphers | (handout on this) | - | Do Barr p. 80: 7 using the spreadsheet. Hand in with the rest of your homework |
| 2 | Th 9/27 | The Hill cipher | - | Barr 2.9 | HW A: p.171: 1ab, 2ab, 3ab, 4 (for 3ab) (due 10/4) |
| 3 | Th 10/4 | [no class] | - | - | HW B: Barr p. 173: 5, 6, 8, 9. |
| 4 | Th 10/11 | Known plaintext attack on Hill cipher | - | Barr p. 170 | Finish correcting Barr p. 179; also finish HW B. |
| 5 | Th 10/18 | Polynomials with coefficients mod 2: adding, multiplying, dividing | - | - | - |
| 6 | Th 10/25 | Characteristic polynomial of a LFSR diagram. Did 3-bit LFSR with taps at positions 1, 2 and 3. | - | - | HW C: 1. Is the characteristic polynomial of 3-bit LFSR with taps at positions 1 and 3 irreducible? Try to factor it. |
| - | - | - | - | - | (con't) 2. Completely analyse the 3-bit LFSR with taps at positions 2 and 3: (a) Is the output sequence of maximal length? (b) Find its characteristic polynomial. (c) Is it irreducible? Try to factor it. (due 11.1) |
| 7 | Th 11/1 | Introduction to Maple. To do modular arithmetic mod 5, just type "mod 5" at the end of the command | Handout with this title, also exercises (don't hand in) | - | - |
| 8 | Th 11/8 | Maple (con't): Linear algebra | Handout with this title | - | HW D: Do the following problems in Barr using Maple: p. 80: 2, 3, 4; p. 171: 1ab, 2ab, 3ab, 4. Print this out and hand it in. You've already done these problems by hand, so check that the Maple answers agree with these. (due 11/12) |
| 9 | Th 11/15 | Knapsack ciphers using Maple | Handout with this title (to come) | - | HW E: (1) Using Maple, make your private sequence, modulus and multiplier. Print out, and also save on your webspace. (2) Make your public sequence, and send to me and I will put it on our website. (3) Send a message to someone else in the class, and also receive one. (Just one or two letters are enough.) |
| - | - | - | - | - | Table of public knapsack sequences |
| 10 | Th 11/29 | - | - | - | - |
| 11 | Th 12/6 | - | - | - | - |
| - | - | - | - | - | Table of public RSA keys |