A Quick History of Cryptography

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Encryption is what makes your personal data secure when you are shopping or banking online. It scrambles data such as your credit card details and home address to ensure hackers cannot misuse this information. Nowadays, encryption involves powerful processors and some equally powerful brains. But it was not always so complicated.

Approximately 600 BC: The ancient Spartans used a device called a scytale to send secret messages during battle. This consists of a leather strap wrapped around a wooden rod. The letters on the leather strip are meaningless when it is unwrapped, and only if the receiver has the correctly sized rod does the message make sense and can be read.

60 BC: Julius Caesar invents a substitution cipher that encodes a message by shifting characters by three places: A becomes D, B becomes E, and so on.

1553: Giovan Battista Bellaso creates the first cipher to use a proper encryption key — an agreed-upon keyword that the recipient needs to know if he or she aims to decode the message.

1854: Charles Wheatstone invents the Playfair Cipher, which encrypts sets of letters instead of single ones and is, therefore, harder to crack.

1917: An American, Edward Hebern, invents the electro-mechanical machine in which the key is held in a rotating disc. It is the first example of the use of a rotor machine for encryption. It encodes a substitution table that is modified every time a new character is typed.

1918: German engineer Arthur Scherbius invents the Enigma machine for commercial use. Instead of the one rotor utilized by Hebern’s machine, it uses several. Recognizing its genius, the German military starts to use it to send encoded transmissions.

1932: Polish cryptographer Marian Rejewski discovers how Enigma operates. In 1939, Poland shared this information with the French and British intelligence services, enabling cryptographers like Alan Turing to figure out how to crack the key, which changed every day. It proved crucial to the Allies’ World War II victory.

1945: Claude E. Shannon of Bell Labs wrote an article called “A mathematical theory of cryptography”. It is considered to be the starting point of modern cryptography.

The early 1970s: IBM creates a ‘crypto group,’ which creates a block cipher to protect the company’s customers’ data. In 1973, the US adopted it as a national standard — the Data Encryption Standard, or DES. It remained in use until it was cracked in 1997.

2000: DES was succeeded by the Advanced Encryption Standard, or AES, which is found through a competition open to the public. Nowadays, AES is available royalty-free worldwide and can be used in classified US government information.

Nowadays: As more and more services move to the cloud, encrypting data in transit became increasingly more important, and cryptographers are constantly developing and improving solutions to this challenge. Blockchain, secret contracts, and many other cryptographical solutions will lead the way in the next chapter of the evolution of encryption.

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