A Brief History of Cryptography - Aisha Khaled

A Brief History of Cryptography

The earliest form of cryptography was the simple writing of a message, as most people could not read. In fact, the very word cryptography comes from the Greek words kryptos and graphein, which mean hidden and writing, respectively.

Early cryptography was solely concerned with converting messages into unreadable groups of figures to protect the message’s content during the time the message was being carried from one place to another. In the modern era, cryptography has grown from basic message confidentiality to include some phases of message integrity checking, sender/receiver identity authentication, and digital signatures, among other things.

The need to conceal messages has been with us since we moved out of caves, started living in groups and decided to take this civilization idea seriously. As soon as there were different groups or tribes, the idea that we had to work against each other surfaced and was proliferated, along with rank violence, secrecy, and crowd manipulation. The earliest forms of cryptography were found in the cradle of civilization, which comes as no surprise, including the regions currently encompassed by Egypt, Greece and Rome.

The Greek’s idea was to wrap a tape around a stick, and then write the message on the wound tape. When the tape was unwound, the writing would be meaningless. The receiver of the message would of course have a stick of the same diameter and use it to decipher the message. The Roman method of cryptography was known as the Caesar Shift Cipher. It utilized the idea of shifting letters by an agreed upon number (three was a common historical choice), and thus writing the message using the letter-shift. The receiving group would then shift the letters back by the same number and decipher the message

In modern times, the public key method of cryptography has seen wide adoption. The use of a common public key and a private key held only by the sender is in use today as a form of asymmetric encryption; one of the uses of this method is for the sender to use the private key to encrypt the message and then anyone who receives the message uses the public key to decipher it. In this way, the receiver knows who the message had to come from.

In conclusion, it is somewhat surprising how limited the history of this very important topic is. No doubt cryptography and in a greater sense, cryptology, has played an enormous role in the shaping and development of many societies and cultures. Cryptography  by its very nature, suggests secrecy and misdirection; therefore, the fact that the history of this topic is short and somewhat inaccessible is of no great surprise. Perhaps it is itself coded in what is has already been written.

If you want to know more fascinated stories about cryptography I suggest you go watch the movie that Shaikha Al Khazraji post "The Lmitation Game".

Resources: http://www.studentpulse.com/articles/41/a-brief-history-of-cryptography