Classical Cryptography

Classical cryptography is the best starting point for learning cryptosystems without prior knowledge of cryptography and high level mathematics.  Here we will selectively review classical cryptosystems. By classical cryptography we mean the cryptosystems are pencil-and-paper based and used until the middle of twentieth century. We have included shift, affine, simple substitution, transposition, Hill and Vigenère ciphers. We have included extensive looks at each of these  cryptosystems, touching on categories such as a basic description and history of the cipher, the advantages and disadvantages of using the cipher, and examples to demonstrate how the encryption and decryption works for each type. 

Along with the written elements, we have also included interactive demonstrations of the cryptosystem. The JavaScript and Java Applet demos should help exemplify the advantages and disadvantages of each cipher.