Towards Efficient Verification of Constant-Time Cryptographic Implementations
<|reference_start|>Towards Efficient Verification of Constant-Time Cryptographic Implementations: Timing side-channel attacks exploit secret-dependent execution time to fully or partially recover secrets of cryptographic implementations, posing a severe threat to software security. Constant-time programming discipline is an effective software-based countermeasure against timing side-channel attacks, but developing constant-time implementations turns out to be challenging and error-prone. Current verification approaches/tools suffer from scalability and precision issues when applied to production software in practice. In this paper, we put forward practical verification approaches based on a novel synergy of taint analysis and safety verification of self-composed programs. Specifically, we first use an IFDS-based lightweight taint analysis to prove that a large number of potential (timing) side-channel sources do not actually leak secrets. We then resort to a precise taint analysis and a safety verification approach to determine whether the remaining potential side-channel sources can actually leak secrets. These include novel constructions of taint-directed semi-cross-product of the original program and its Boolean abstraction, and a taint-directed self-composition of the program. Our approach is implemented as a cross-platform and fully automated tool CT-Prover. The experiments confirm its efficiency and effectiveness in verifying real-world benchmarks from modern cryptographic and SSL/TLS libraries. In particular, CT-Prover identify new, confirmed vulnerabilities of open-source SSL libraries (e.g., Mbed SSL, BearSSL) and significantly outperforms the state-of-the-art tools.<|reference_end|>
@article{cai2024towards,
    title={Towards Efficient Verification of Constant-Time Cryptographic
  Implementations},
    author={Luwei Cai and Fu Song and Taolue Chen},
    journal={arXiv preprint arXiv:2402.13506},
    year={2024},
    archivePrefix={arXiv},
    eprint={2402.13506},
    primaryClass={cs.CR cs.SE}
}