You donโ€™t need to be a spy โ€“ or hopelessly paranoid โ€“ to want to keep your data safe from prying eyes. If your computer was stolen or your emails intercepted, the damage could be serious โ€“ especially if you use your PC for business. The last thing you want is for your competitors to get advance warning of new products, prices or contracts. If you use encryption software, they wonโ€™t be able too.

Egyptian Encryption

Encryption is a way of scrambling text or data. If you know the right code, you can unscramble it to see the original message. If you donโ€™t know the code, all you see is gibberish. If youโ€™ve ever bought something from an online shop, youโ€™ve probably used encryption without realizing it; secure web servers encrypt your details to keep your credit card details safe from interception. Online banking uses encryption, and both individuals and companies are embracing encryption software in increasing numbers; the technology is also used for digital signatures that prove you are who you claim to be.

These days encryption is a high tech affair, but cryptography โ€“ the science of encrypting and decrypting messages โ€“ has been around for centuries. The Egyptians were using an early form of encryption as long ago as 1900 BC, and Julius Caesar (100BC โ€“ 44BC) routinely encrypted his official messages. The technology used was very basic, but also very effective.

Breaking the Enigma

In 1939, Nazi U-boats were wreaking havoc on military and merchant ships. The submarines appeared from nowhere, torpedoing entire fleets before disappearing beneath the waves. Allied commanders knew that if they could break the Enigma code, they could listen in on the U-boatsโ€™ orders and discover where they were. There was only one problem; the odds against breaking the Enigma code were 150 000 000 000 000 000 000 to 1.

The Allies recruited some of the countryโ€™s brightest mathematicians and sent them to Bletchley Park, a mansion in Buckinghamshire that had been commandeered by the military. Their mission was simple; to crack the Enigma code.

Cracking the Enigma code was no simple matter. Enigmaโ€™s complexity was bewildering and the codes changed daily. The code breakers built a Bombe.

Bombes Away

The Bombe was the work of mathematician Alan Turing, the father of modern computing. Based on the pioneering work of Polish code breakers, the Bombe was an early form of computer that could crunch numbers at a dizzying speed. In 1940 the Enigma code was defeated. Not only had Turing invented the forerunner of todayโ€™s PC, he also proved that no matter how clever the code, any Private Key Cryptography can be broken if you chuck enough processing power at it.