Continual Leakage-Resilient Hedged Public-Key Encryption. (13th February 2021)

• Record Type: Journal Article
• Authors: Huang, Meijuan; Yang, Bo; Zhou, Yanwei; Hu, Xuewei
• Is Part Of: Computer journal. Volume 65:Number 6(2022)
• Page Start: 1574
• Page End: 1585
• Publication Date: 2021-02-13
• Subjects: hedged public-key encryption -- all-but-one trapdoor functions -- continual leakage-resilience -- hedged security -- randomness failures; Computers -- Periodicals; 005.1
• DOI: 10.1093/comjnl/bxaa204
• Languages: English
• ISSNs: 0010-4620

Abstract

Abstract: Hedged public-key encryption (HPKE), introduced by Bellare et al . (ASIACRYPT 2009), provides useful security when the per-message randomness fails to be uniform due to faulty implementations or adversarial actions. The HPKE scheme achieves IND-CPA (chosen plaintext attack) security when the randomness they used is of high quality, but, when the randomness is poor quality, rather than breaking completely, it achieves a weaker but a useful notion of security called IND-CDA (chosen distribution attack) as long as the message and randomness together have sufficient min-entropy. However, little research on HPKE in the presence of key leakage was done. In this paper, we study HPKE featuring key leakage-resilience and formulate appropriate security notion for key leakage-resilient HPKE. We work in the continual key leakage model where the secret key is refreshed periodically and an adversary can learn arbitrary but bounded leakage on the secret key between the updates. We present two generic constructions of continual leakage-resilient HPKE in the standard model by using a continual leakage-resilient all-but-one lossy trapdoor function. Finally, we give an instantiation of leakage-resilient HPKE under the linear assumption in bilinear groups.