More Like this

1. Witness Authenticating NIZKs and Applications

   https://doi.org/10.1007/978-3-030-84259-8_1  

   Feng, Hanwen; Tang, Qiang (August 2021, Annual International Cryptology Conference)

   We initiate the study of witness authenticating NIZK proof systems (waNIZKs), in which one can use a witness w of a statement x to identify whether a valid proof for x is indeed generated using w. Such a new identification functionality enables more diverse applications, and it also puts new requirements on soundness that: (1) no adversary can generate a valid proof that will not be identified by any witness; (2) or forge a proof using her valid witness to frame others. To work around the obvious obstacle towards conventional zero-knowledgeness, we define entropic zero-knowledgeness that requires the proof to leak no partial information, if the witness has sufficient computational entropy. We give a formal treatment of this new primitive. The modeling turns out to be quite involved and multiple subtle points arise and particular cares are required. We present general constructions from standard assumptions. We also demonstrate three applications in non-malleable (perfectly one-way) hash, group signatures with verifier-local revocations and plaintext-checkable public-key encryption. Our waNIZK provides a new tool to advance the state of the art in all these applications. 

   more » « less
2. Batch Arguments to NIZKs from One-Way Functions

   Bradley, Eli; Waters, Brent; Wu, David J (November 2024, Theory of Cryptography Conference)
3. Dual-Mode NIZKs: Possibility and Impossibility Results for Property Transfer.

   Arte, Vivek; Bellare, Mihir (December 2020, Progress in Cryptology - INDOCRYPT 2020 - 21st International Conference on Cryptology in India, Proceedings. Lecture Notes in Computer Science, Springer)

   Bhargavan, Karthikeyan; Oswald, Elisabeth; Prabhakaran, Manoj (Ed.)

   This paper formulates, and studies, the problem of property transference in dual-mode NIZKs. We say that a property P (such as soundness, ZK or WI) transfers, if, one of the modes having P allows us to prove that the other mode has the computational analogue of P, as a consequence of nothing but the indistinguishability of the CRSs in the two modes. Our most interesting finding is negative; we show by counter-example that the form of soundness that seems most important for applications fails to transfer. On the positive side, we develop a general framework that allows us to show that zero knowledge, witness indistinguishability, extractability and weaker forms of soundness do transfer. Our treatment covers conventional, designated-verifier and designated-prover NIZKs in a unified way. 

   more » « less
4. New Techniques for Preimage Sampling: Improved NIZKs and More from LWE

   Waters, Brent; Wee, Hoeteck; Wu, David J (May 2025, EUROCRYPT)