1. Guess My Word part 2 Add extra privacy to our communications! – how is it done?

2. Code Table A1H8O15V22 B2I9P16W23 C3J10Q17X24 D4K11R18Y25 E5L12S19Z26 F6M13T20space0 G7N14U21 Code Table: Translate between English and numbers. “GOOD”  [7, 15, 15, 4] [13, 1, 20, 8]  “Math”

3. [-6, 16, -10, 36 ] Use matrix A to solve the word:  “HARD” [8, 1, 18, 4 ]

4. [-8, 36, -4, 44, 41 10 ] [?, ?, ?, ? ] Matrix A works like a “key”. [#1, #2, #3, #4 ]  “REVIEW” A1H8O15V22 B2I9P16W23 C3J10Q17X24 D4K11R18Y25 E5L12S19Z26 F6M13T20space0 G7N14U21

5. How is it done? Math is working behind the scene! If than

6. 1.Pick a 4 to 6 letter word. [3 21 20 5] 2.Pick a simple 2x2 matrix – call it matrix “S” for secret. (Make sure your matrix “S” is invertible!) A1H8O15V22 B2I9P16W23 C3J10Q17X24 D4K11R18Y25 E5L12S19Z26 F6M13T20space0 G7N14U21

7. 4.Put the result above in sequence into a new 1xN matrix – matrix “E” for Encrypted. My E=[-45 -18 -30 5] 5.Calculate the inverse matrix of “S” – the inverse of “S” is matrix “K” for Key. 3.Multiply matrix S to your original word, two letters at a time. (Note: If your word has odd number of letters, add a space in the end to make it even.)

8. Now give the encoded sequence “E” and your key matrix “K” to others and see whether they can figure out what your original word is! A1H8O15V22 B2I9P16W23 C3J10Q17X24 D4K11R18Y25 E5L12S19Z26 F6M13T20space0 G7N14U21