Cryptography in details

It is believed that the oldest known text to contain one of the vital components of cryptography, a modification of the text, occurred some 4000 years ago in the Egyptian town of Menet Khufu where the hieroglyphic inscriptions in the region of the tomb of the nobleman KHNUMHOTEP II were written plus a number of unfamiliar symbols to confuse or nameless the meaning of the inscriptions.

In 5BC the Spartans, a warrior bureau famed for their austere lifestyle, bravery, and proficiency in scuffle, developed a cryptographic device to send and realize unidentified messages. This device, a cylinder called a Scytale, was in the possession of both the sender and the recipient of the declaration. To prepare the statement, a narrow strip of parchment or leather, much subsequent to a militant-hours of hours of day paper streamer, was wound as regards the Scytale and the declaration was written across it. Once unwound, for transport to the beneficiary, the photo album displayed unaccompanied a sequence of useless letters until it was just just about speaking-wound onto a Scytale of exactly the connected diameter. The code, produced by unwinding the cassette, was a TRANSPOSITION cipher, that is, one where the letters remain the same but the order is changed. This is still the basis for many popular futuristic-hours of daylight techniques.

The late gathering major ingredient of these campaigner techniques is the ADDITIVE/SUBSTITUTION cipher. Although the Greek writer Polyibus described a substitution technique, its first recorded use was by Julius Caesar. Messages were encoded by substituting the letter in the text by one that is three positions to the right. A became D, V became Y etc. The excuse why a substitution of three letters, and not four, two or six, was chosen has never been explained.

In an essay written in 1466, an Italian Leon Battista Alberti who is often called the father of western cryptography, described the construction of a cypher disk, founding the concept of POLY ALPHABETIC ciphers. Although he had made the most important encourage in cryptography in at least five hundred years, he did not produce his concept. It was left for others, the best known physical the French cryptographer Blaise de Vigenere to devise a practical poly alphabetic system which bears his declare, the VIGENERE SQUARE. At the time, and for a considerable era afterwards this technique was believed to be unbreakable (Le Chiffre Indechiffrable). There was however a disease in this cipher waiting to be exploited because the cyphertext produced by this method was vulnerable to the yet undiscovered statistical ferociousness.