This discussion of ciphers vs puzzles has reminded me of one of my favorite books growing up. It was Helen Fouché Gaines Elementary Cryptanalysis. I found it in

This discussion of ciphers vs puzzles has reminded me of one of my favorite books growing up. It was Helen Fouché Gaines Elementary Cryptanalysis. I found it in the library in 1962 and treasured the copy my Aunt purchased for me. This book predates the age of computers so every chapter introduces the common ciphers, including, military and diplomatic ones, in use at the time (I believe the first edition was written in 1943) along with the methods used to attack them. Over time I worked my way through the exercises that appear at the end of each chapter. Computers make light work of these challenging puzzles now, but it’s still fun to write programs to break these old cipher systems. Around 1987, I approached a very prominent professor in my CS program about being my Ph.D. dissertation advisor for a research project on Cryptography. He said that I should work in another area because cryptography had all been figured out and it didn’t look like there was anything interesting left in that field!