The focus of this work is on ciphers. This book is composed of the history of the cipher as well as examples of where and how the code was mostly used. The reader can find the description of a
specific cipher on the left side of the spread and an example of the code on the opposite side of the page. Without the key it is very difficult to decrypt the secret message. To implement a book cipher,
each word in the secret message is replaced with a number or graphic note which represents the same word in the book. If you have difficult time decoding a secret message you can go to the back of the book
and find the answers.
Instructor: Simon Johnson | 2013