Abstract. We present a simple and efficient post-quantum verifiable decryption scheme improving upon the framework by Gjøsteen et al. (ACISP 2022) based on a passively secure distributed decryption scheme and MPC-in-the-Head techniques. Our improvements lead to 440x smaller proof sizes compared to Gjøsteen et al., by adapting the nearly linear decryption algorithm by Boyle et al. (Eurocrypt 2019). This furthermore lead to 10x decrease in proof size compared to the state-of-the-art schemes by Silde (Voting 2022) and Lyubashevsky et al. (PKC 2021).
Joint work with: Thomas Haines, Peter B. Rønne, Tjerand Silde
WPEC 2024: NIST Workshop on Privacy-Enhancing Cryptography 2024. Virtual, 2024-Sep-24–26.
NIST Workshop on Privacy-Enhancing Cryptography 2024
Starts: September 24, 2024Virtual
Security and Privacy: cryptography