ACT : An Ultra Light Weight Block Cipher For Internet of Things

Abstract

In this paper an ultra light weight block cipher named ACT is proposed. This cipher is exclusively designed to operate in resource constrained environments. ACT is a 64 bit substitution permutation network(SPN) with a key length of 80 bits. The construction of ACT requires only 1481 Gate Equivalents (GE). The new 4 bit substitution box (sbox) introduced in this design achieves minimal differential and linear cardinalities. The Permutation layer proposed in this design, combined with sbox properties offers excellent security performance which is indicated by large numbers of both linear and differential active sboxes in a fewer number of rounds. The minimum number of rounds required for a full diffusion of data is just 3. Key schedule and permutation layer together provides excellent resistance against biclique attacks. The dynamic power consumption of ACT is just 30 mW which is lesser compared to other block ciphers like PRESENT, LED etc. The details of differential, linear, biclique and algebraic cryptanalyses are given in this paper. Comparison of parameters with other block ciphers is also given.