Although most modern encryption techniques are done by computers, ciphers were already being used to encode messages since before the ancient Greeks, around 400 BC. The well-known Roman politician Julius Caesar made great use of substitution ciphers, replacing each letter in a message with the letter that was located three places further down the alphabet.
For instance, if we use the same technique to encrypt the word BINANCE, the resulting ciphertext would be ELQDQFH. This message looks meaningless to a third party but can be easily decrypted by the intended recipient since he already knows the shift number employed by the sender to encrypt it.
The science of using mathematical theories and computation in order to encrypt and decrypt information.
Conversion of information or data into a secure code in order to prevent unauthorised access to the informa...