Cryptographic hash mode

Hash functions are primarily used to compress a message to a fixed-length digest. In cryptographic hash mode, block ciphers are used as a compression function to produce a hash of plaintext.

With this, we have now concluded the introduction to block ciphers. In the following section, you will be introduced to the design and mechanism of a currently market-dominant block cipher known as AES.

Before discussing AES, however, some history is presented about the Data Encryption Standard (DES) that led to the development of the new AES standard.