Week 2, Tuesday 2.5-2.8

The book explained how to encrypt the ADFGX Cipher very well. However, the decryption method was quite confusing. Could you explain pg. 33 2nd to last paragraph, starting with "Here is the one technique that was......" The codes keep getting more and more complicated. As I read them, I'm sometimes stunned at the complexity. After reading the Hill Cipher and reviewing my Linear Algebra the cipher methods can become complex very quickly. I feel that many of the ways to code break use trial and error as well as luck. Did people 100 years ago really sit down and use brute force to reveal the key? Shannon's rule of diffusion and confusion seems to be a simple yet safe method of checking one's code to make sure it is foolproof. I will start to analyze future codes in the cryptography book using this rule.