Several thousand years ago, when a King wanted to send a message of utmost security to another person or king, a slave of the king would have his head "shaved" and the message would be permanently tattooed on his head. Once the hair regrew and covered the message, only then would he be sent to deliver the message. His head would be shaved again to read the message. Once the message was read, his head would be cut off to protect the message from falling into wrong hands. Hence the term "Don't cut off the messenger's head" is oft used when you have bad news to deliver.

Hollywood has produced several movies about encryption. In fact, the number of movies about encryption has risen. It's the stuff of spies, encoding a secret message that can only be decoded by the other party, that is unless you have a secret decoder ring and can break the code or steal the machine from a submarine and get it into the code breakers hands.

During World War Two, the German Nazi regime had the Enigma...