Cumulant Expansion of Mutual Information for Quantifying Leakage of a Protected Secret

TL;DR

This paper introduces a cumulant expansion method to quantify information leakage in cryptographic implementations, especially effective when the signal-to-noise ratio is low, by expanding key information measures in terms of moments and cumulants.

Contribution

It presents a novel approach using cumulant expansion to evaluate mutual information leakage in cryptography under low signal-to-noise conditions.

Findings

Effective quantification of leakage at low SNR

Provides a new analytical tool for cryptographic security assessment

Enhances understanding of information leakage mechanisms

Abstract

The information leakage of a cryptographic implementation with a given degree of protection is evaluated in a typical situation when the signal-to-noise ratio is small. This is solved by expanding Kullback-Leibler divergence, entropy, and mutual information in terms of moments/cumulants.