A BRIEF HISTORY OF THE SCIENCE OF SECRECY
by Simon Singh
Ever since humans learnt to write, I suspect that they have been writing in codes. As soon as a sensitive message was inscribed on a clay tablet or written on a piece of papyrus, then it must have been foremost in the sender’s mind that it should not be intercepted and read by a rival. The message might have been a military plan, a political plot or a letter to secret lover, but in every case the necessity to encrypt was obvious.

Today, in the Information Age, the need to protect communications from prying eyes is greater than ever before. Cryptography, the science of encryption, plays a central role in mobile phone communications, pay-TV, e-commerce, sending private e-mails, transmitting financial information, and touches on many aspects of our daily lives.

Today’s technologies can be traced back to the earliest ciphers, and have grown as a result of evolution. The first ciphers were cracked, so new, stronger ciphers emerged. Codebreakers set to work on these and eventually found flaws, forcing cryptographers to invent better ciphers and so on. For example, when the monoalphabetic substitution cipher was cracked, the polyalphabetic was invented.