Non-Malleable Functions and Their Applications

We formally study “non-malleable functions” (NMFs), a general cryptographic primitive which simplifies and relaxes “non-malleable one-way/hash functions” (NMOWHFs) introduced by Boldyreva et al. (ASIACRYPT 2009) and refined by Baecher et al. (CTRSA 2010). NMFs focus on deterministic functions, rather than probabilistic one-way/hash functions considered in the literature of NMOWHFs. We mainly follow Baecher et al. to formalize a game-based definition. Roughly, a function f is non-malleable if given an image y∗ ← f(x∗ ) for a randomly chosen x∗ , it is hard to output a mauled image y with a φ from some transformation class s.t. y = f(φ(x∗ )). A distinctive strengthening of our non-malleable notion is that φ(x∗ ) = x∗ is always allowed. We also consider adaptive non-malleability, which stipulates that non-malleability holds even when an inversion oracle is available. We investigate the relations between non-malleability and one-wayness in depth. In the non-ada...

• Type: Journal
• Year: 2016
• Where: PKC
• Authors: Yu Chen, Baodong Qin, Jiang Zhang, Yi Deng, Sherman S. M. Chow
• Keywords: Cryptology, PKC 2016