Cipher

The cipher is any method that is used for encryption and decryption. The meaning of the words "cipher" and "algorithm" can often be interchanged, since they both mean the same thing. A cipher is the algorithm or function that creates the encryption and the decryption. These algorithms can range in complexity from the simple and elegant to the incredibly complicated and convoluted. Note that complicated ciphers do not always yield the strongest or most secure encryption. In fact, the inner workings of a good cipher system should lend itself to scrutiny and thus improvement.

Depending on their mode of implementation, ciphers can be categorized in several ways-for example, concealment ciphers versus running key ciphers, substitution ciphers versus transposition ciphers, or stream ciphers versus block ciphers.