A Hybrid Attack on Small Private Exponent RSA via Continued Fractions and Lattices
Mengce Zheng, Yansong Feng, Abderrahmane Nitaj, Yanbin Pan · Cryptography · 2026
In this study, we propose a hybrid cryptanalytic technique targeting the RSA cryptosystem when instantiated with small private exponents. By integrating the continued fraction approach with Coppersmith’s lattice-based technique, we formulate a novel vulnerability framework. Utilizing an innovative relationship extracted from continued fraction convergents, we deduce an improved upper bound for the secret key: d