ABSTRACT
Cryptography, the art of “secret writing,” has existed for almost as long as writing itself. Originally, the
use of symbols to represent letters or words in phrases was a skill reserved for scribes or learned clerics.
However, for a scribe’s work to be truly useful, others needed the ability to read the scribe’s work. As
standardized writing and reading skills became more widespread, the risk of unauthorized reading
increased. Primarily for purposes of political intrigue and military secrecy, practical applications of secret
writing evolved. There are examples of simple alphabetic substitution ciphers dating back to the time of
Julius Caesar. Julius Caesar is honored today by our naming an entire class of mono-alphabetic
substitution ciphers after him. The following (translated into our modern alphabet) is an example of
a cipher he is believed to have used:
