History of Cryptography

Cryptography has been around for some time now, and in comparison to other disciplines, it is still young. For about a hundred years now, people have used this technique to hide messages especially sensitive information.

How Far Back Does Cryptography Date?

Pieces of evidence throughout history have shown the use of cryptography back in the earlier times. Around 1900 BC in Egypt, Khnumhotep II’s tomb has inscriptions that used unusual hieroglyphics. Researchers claim that the inscriptions were not necessarily meant to hide sensitive information, but only to make the writings look dignified.

Early civilizations also show the use of cryptography. A good example is that of the Arthshashtra which was written by Kautalya. It is about statecraft which describes espionage services in India. The writer also mentioned about spies getting assignments in codes or secret writing.

Julius Caesar was also noted for sending secret or encrypted messages to his generals back in 100 BC which was popularly known as ‘Caesar cipher’. For every character, there is a matching substitute cipher. The encrypted message is the cipher text that is unreadable. With the Caesar cipher, the characters were simply shifted three (3) places. For instance, the letter ‘A’ is replaced by the letter ‘D’, ‘B’ by ‘E’, ‘C’ by ‘F’, until all the letters are used.

Maintaining Secrecy

The system’s secrecy is very important because once it is made known to other people the encrypted messages can be easily decoded or decrypted. Therefore, only authorized people should be aware of the system and the keys.

It was during the 16th century when an encryption key was used to cipher plain text by Vigenere. However, it was also quite easy to decrypt. Still, he was the first person to introduce the encryption key which is being used to date.

During the 19th century, another attempt in cryptography was designed by Hebern. His work was called ‘Hebern rotor machine’ and it was basically an electro-mechanical contraption. The rotating discs embed the secret key, but due to letter frequencies, the cipher was also broken with ease.

After World War I, Arthur Scherbius, a German engineer invented the Enigma machine. The machine was used until World War II, and it had 3-4 rotors. Poland was able to break the cipher and British cryptographers adopted the technology to design an effective way to obtain daily keys. Until the Second World War, cryptography was used mainly by the military.

By 1970, IBM created the crypto group which designed ‘Lucifer’. The NIST, formerly known as National Bureau of Standards, accepted the Lucifer and changed its name to Data Encryption Standard or DES. A comprehensive search attack was able to break the DES. After this, NIST searched for another block cipher and it accepted Rijndael in the year 2000. The cipher was called Advanced Encryption Standard or AES.

Until today, cryptographers follow the Kerckhoff’s Principle which believes that the message’s secrecy should depend on the key’s secrecy and not that of the encryption system. It is always best to use ciphers that are accepted as a standard and are reviewed publicly. Now that you know a bit of the history of cryptography, you will be able to appreciate its worth regardless of the industry that you belong.