Paper 2023/1198

A Methodology to Achieve Provable Side-Channel Security in Real-World Implementations

Abstract

Physical side-channel attacks exploit a device's emanations to compromise the security of cryptographic implementations. Many countermeasures have been proposed against these attacks, especially the widely-used and efficient masking countermeasure. While theoretical models offer formal security proofs, they often rest on unrealistic assumptions, leading current approaches to prove the security of masked implementations to primarily rely on empirical verification. Consequently, the literature still lacks a well-defined framework for implementing proven secure constructions on physical devices. In this paper, we present a comprehensive methodology to transform an abstract circuit into a physical implementation secure against side-channel attacks. We introduce new tools for adapting the ideal noisy leakage model to practical scenarios. We also highlight the design objectives for embedded devices to achieve high levels of security, while acknowledging the limitations and challenges in applying leakage models in practice. Our aim is to demonstrate the possibility of bridging theory and practice, encouraging further research to achieve practical implementations proven secure against side-channel attacks without relying on ideal assumptions about the leakage.