Power analysis based reverse engineering on the secret round function of block ciphers

Abstract

Side Channel Analysis (SCA) has become a new threat to the hardware implementations of encryption algorithms. The reverse engineering has been adopted to explore the unknown part of the encryption algorithms. The existing SCAs for reverse engineering depend on the leakage models in a large extent and mainly focus on the single component of the algorithms while the other parts of the target algorithm are known. In this paper, we present a more general and feasible reverse analysis by combining the mathematical methods and the SCA methods. We use the strict avalanche criterion for the non-linear operations of block ciphers and apply the power analysis to reverse the structure parameters. We propose a new reverse analysis method to reduce the dependency on the leakage models, which can be combined with the structure cryptanalysis to reverse the internal parameters of the linear and non-linear operations. We finally achieve the reverse analysis on the unknown round function of block ciphers.