Cryptography deals with algorithms. Many different algorithms are used for different purposes and circumstances. The algorithms most widely used in computer and network security are
Digital signature algorithms
Message digest/one-way hash algorithms
Encryption algorithms may be divided into two types: symmetric (shared secret key) and asymmetric (public key). Symmetric algorithms may also be categorized into two other groups: block ciphers (algorithms working with blocks of data) and stream ciphers (algorithms working with data streams).
Message digest/one-way hash algorithms are used to generate digital “fingerprints” of data. They are described in the “Message Digest and One-Way Hash Algorithms” section. ...