Codes

I'm teaching my Algebra 2 kids about cryptography (the study of codes). It's similar to the Enigma machine from World War II. Here's how it works (put simply):





1. Assign numbers to the alphabet.
2. Write a message.
3. Change each letter to its corresponding number.
4. Put numbers into a Matrix (a rectangular "paragraph" of numbers. See above.).
5. Multiply the matrix by another matrix.
6. Send new numbers.
7. Receiving people multiply by the inverse matrix (to undo and get message).
8. Change numbers back to letters.

The trick is that no one "unauthorized" can know what the second matrix was in Step 5. Polish Mathematicians cracked the Engima's code. Go math geeks!

Movie of the Day: Matrix, of course.