QFESTA: Efficient Algorithms and Parameters for FESTA using Quaternion Algebras

ePrint Report: QFESTA: Efficient Algorithms and Parameters for FESTA using Quaternion Algebras

Kohei Nakagawa, Hiroshi Onuki

In 2023, Basso, Maino, and Pope proposed FESTA~(Fast Encryption from Supersingular Torsion Attacks), an isogeny-based public-key encryption (PKE) protocol that uses the SIDH attack for decryption. In the same paper, they proposed a parameter for that protocol, but the parameter requires high-degree isogeny computations. In this paper, we introduce QFESTA (Quaternion Fast Encapsulation from Supersingular Torsion Attacks), a new variant of FESTA that works …

algorithms attack attacks decryption encryption eprint report fast key parameter pope protocol public report