This book constitutes the thoroughly refereed post-conference proceedings of the 20th
International Workshop on Fast Software Encryption held in Singapore March 11-13 2013. The
30 revised full papers presented were carefully reviewed and selected from 97 initial
submissions. The papers are organized in topical sections on block ciphers lightweight block
ciphers tweakable block ciphers stream ciphers hash functions message authentication codes
provable security implementation aspects lightweight authenticated encryption automated
cryptanalysis Boolean functions.
