Improvement on Bit Diffusion Analysis of Π-Cipher

Abstract

π-Cipher, designed by Gligoroski et al., is a second round candidate of the CAESAR competition. The designers analyzed the bit diffusion of the cipher by examining the ∗ operation and 1 round π-function. We improve this analysis by applying Strict Avalanche Criterion (SAC) test to ∗ operation and reduced round versions of π-function for π 16-Cipher. We found out that ∗ operation fails SAC test whereas all versions of π-function for π 16-Cipher pass the test. © 2017 Mathematical Institute, Slovak Academy of Sciences.