What is a Cipher?
Ciphers are the specific algorithms which are used to encrypt and decrypt data. A cipher is series of well-defined steps that can be followed as a procedure to encrypt and decrypt messages. Cipher Methods Transposition Cipher · No letters are replaced. They are simply rearranged. · E.g.: Backward cipher Rail fence cipher Scytale DES/3DES One Time Pad · Key is consisting of arbitrarily long, non-repeated sequence of numbers. · Key length = message length in number of characters · Key is combined character by character with plain text by using XOR to produce cipher text. · Many Time Pods – if the key is used for more than once.