Tight Leakage-Resilient Identity-based Encryption under Multi-challenge Setting
Cailing Cai, Xianrui Qin, Tsz Hon Yuen, Siu Ming Yiu · Proceedings of the 2022 ACM on Asia Conference on Computer and Communications Security · 2022
In this work, we present the first leakage-resilient identity-based encryption (LR-IBE) scheme that features (almost) tight security under the multi-challenge setting, in which the adversary could receive multiple challenging ciphertexts from multiple users. Meanwhile, our construction enjoys security against chosen-ciphertext attack (CCA) under the Matrix Decisional Diffie-Hellman (MDDH) assumption. Apart from admitting the continual leakage of secret key, we provide strong security via additionally allowing the continual leakage of the master secret key.