By Gordon Rugg and Gavin Taylor
The story so far: We’re working on the D’Agapeyeff Cipher, a short ciphertext that’s never been cracked. It’s a good testbed for codebreaking methods. In this series of articles, we’re collecting together resources about the Cipher for other researchers. In the previous episode, we looked at the methods that D’Agapeyeff described in the first edition of his book Codes and Ciphers, where the D’Agapyeff Cipher appeared. In this episode, we look at the solutions to the worked examples in the same book, to see what insights they might give.
When you’re trying to crack a code, you look for any clues that might possibly give you some insight into the content of the ciphertext. If you know what the text is about, then you can work backwards from that, and improve your chances of finding a solution. That’s why, for a while in World War II, one of the safest postings for a soldier on either side was in an Afrika Korps forward observation post in the Western Desert (hence the title for this episode).