Cryptanalysis of the Speck Family of Block Ciphers

Simon and Speck are two families of ultra-lightweight block ciphers which were announced by the U.S. National Security Agency in June 2013. Yet, the specification discusses only the design and the performance of both cipher families and the task of analyzing their security has been left to the were proposed by the U.S. National Security Agency in June 2013. Yet, the specification paper discusses only the design and the performance of both cipher families, the task of analyzing their security has been left to the research community. In this paper we present conventional differential as well as rectangle attacks for almost all members of the Speck cipher family, where we target up to 11/22, 12/23, 14/16, 15/29, and 18/34 rounds of the 32-, 48-, 64-, 96-, and 128-bit version, respectively.