Sponges and Engines: An introduction to Keccak and Keyak

TL;DR

This paper provides an introductory overview of Keccak and Keyak, focusing on their underlying algorithms, design principles, and constructions for authenticated encryption, including sponge and duplex modes.

Contribution

It offers a comprehensive introduction to the cryptographic primitives Keccak and Keyak, detailing their design components and operational modes for authenticated encryption.

Findings

Explains the sponge and duplex constructions used in Keccak and Keyak.

Describes the permutation functions and their role in security.

Introduces Keyak v2's Motorist mode of operation.

Abstract

In this document we present an introductory overview of the algorithms and design components underlying the Keccac cryptographic primitive and the Keyak encryption scheme for authenticated (session-supporting) encryption. This document aims to familiarize readers with the basic principles of authenticated encryption, the Sponge and Duplex constructions (full-state, keyed as well as regular versions), the permutation functions underlying Keccak and Keyak as well as Keyak v2's Motorist mode of operation.