This document specifies tweakable block ciphers. A tweakable block cipher is a family of n-bit permutations parametrized by a secret key value and a public tweak value. Such primitives are generic tools that can be used as building blocks to construct cryptographic schemes such as encryption, Message Authentication Codes, authenticated encryption, etc.

A total of five different tweakable block ciphers are defined. They are categorized in Table 1.