The Caesar Cipher: Ancient And Simple Yet Effective Cipher Used By Julius Caesar

Conny Waters - AncientPages.com - Ancient Rome’s dictator and general Julius Caesar turned the Roman Republic into the powerful Roman Empire, but he had a lot of enemies.

When he sent messages to his generals he used a simple, yet difficult code to decipher. The Caesar Cipher was long impossible to break.

In most cases Caesar used a type of substitution cipher in which each letter in the plaintext is 'shifted' a certain number of places down the alphabet.

With help of the alphabet, Caesar would write a letter and then shift it 3 times to the right. The letter “B” would become an “E” and so forth. The Caesar cipher is probably the easiest of all ciphers to break.

The action of a Caesar cipher is to replace each plain text letter with a different one a fixed number of places down the alphabet. The cipher illustrated here uses a left shift of three, so that (for example) each occurrence of E in the plain text becomes B in the cipher text.

However, despite being so simple Caesar Cipher did its trick and it was allegedly never cracked by his enemies. Some variation of the cipher was used up to 1915 by the Russians during the First World War, but it did not take long to break.

See also:

Julius Caesar Assassinated – On Mar 15, 44 BC

Julius Caesar Dedicated Temple To Venus Genetrix – On Sep 26, 46 BC

Julius Caesar Defeated “Pompey The Great” At Pharsalus – On August 9, 48 BC

The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, a method originally described by Giovan Battista Bellaso in his 1553 book La cifra del. Sig. Giovan Battista Bellaso. Though the cipher is easy to understand and implement, for three centuries it resisted all attempts to break.  The Caesar Cipher still has modern application in the ROT13 system.

Another method cipher method used by Caesar was to exchange Latin letter against Greek ones.

So it was certainly a simple, but an effective way to send secret messages.

Written by Conny Waters – AncientPages.com Staff Writer

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