The Secrets of Cryptography: The Art of incomprehension by OthersEver since the dawn of history, man needed to protect documents and communications from the eyes and ears of opponents or enemies. Since 1900 B.C, the pharaohs used different hieroglyphs to communicate with their generals. 4000 years later Americans during World War II recruited hundreds of Navajo Indians as operators in radio communications, thanks to their language incomprehensible made military communications secure in the case of tapping by the Japanese.History and the Future.Today cryptography, or the ability to make a message incomprehensible to everyone except the legitimate recipient, is a true science. Below we are presenting a short journey into the history of mystery, maths, and espionage to find out how a cryptosystem is created and how it is used. Which are the safest systems? And how the contribution of an unknown Polish mathematician determines in the fates of World War II. But do not forget that to discover something very private, it is not always necessary to have access to a computer or to an advanced encryption system. Sometimes it’s enough to put to work the intelligence and the trust.Millions of messages permeate each day telecommunications networks. Every day over 150 billion e-mails and 400 million Twitter messages are sent (see for curiosity the statics of worldometers). E-mails and messages, but also banking transactions, telephone calls and even faxes (still). Whose content often needs to be protected from unauthorized interception: from the number of credit cards to conversations among politicians.The protection of these communications is entrusted to a special technique called cryptography. The term comes from Greek, from the union of words cryptos (hidden) and grams (write), secret writing. Cryptography is the art of sending messages (and not just in writing) accessible only to the right recipients.About 400 BC The “sensitive” communications were coded with the skit method. A simple and effective system that for the first time introduced the concept of the decryption key. The message was written from left to right on a leather strap wrapped around a rod so that every row of the stem contained only one letter. If the scroll was opened, the letters were reorganized and the message was no longer readable.Only using a stick identical to that of the sender (key) would enable the recipient to rebuild the message text. In Sparta, this system was used since 400 BC. It is probably the oldest known method of cryptography through transposition. With small changes, this method survived for many centuries alongside the most naive systems. For example, replacing or mixing fonts based on not too complex rules so that the recipient itself could decrypt the message.When the enigma becomes art!Cryptosystems based on replacement of letters were very unreliable. In the early 1930s, German intelligence created the electro-mechanical encryption machine called Enigma. It was a separate typewriter equipped with three different wheels, each of which listed the alphabet characters in a predefined way, and different from that of the standard.