Revision #1 Authors: Noga Amit, Guy Rothblum

Accepted on: 30th May 2024 12:51

Downloads: 48

Keywords:

What are the minimal cryptographic assumptions that suffice for constructing efficient argument systems, and for which tasks? Recently, Amit and Rothblum [STOC 2023] showed that one-way functions suffice for constructing constant-round arguments for bounded-depth computations. In this work we ask: what other tasks have efficient argument systems based only on one-way functions? We show two positive results:

First, we construct a new argument system for batch-verification of $k$ $UP$ statements ($NP$ statements with a unique witness) for witness relations that are verifiable in depth $D$.

Taking $M$ to be the length of a single witness, the communication complexity is $O(\log k) \cdot (M + k \cdot D \cdot n^{\sigma})$, where $\sigma > 0$ is an arbitrarily small constant. In particular, the communication is quasi-linear in the length of a single witness, so long as $k < M / (D \cdot n^{\sigma})$.

The number of rounds is constant and the honest prover runs in polynomial time given witnesses for all $k$ inputs' membership in the language.

Our second result is a constant-round doubly-efficient argument system for languages in $P$ that are computable by bounded-space Turing machines. For this class of computations, we obtain an exponential improvement in the trade-off between the number of rounds and the (exponent of the) communication complexity, compared to known unconditionally sound protocols [Reingold, Rothblum and Rothblum, STOC 2016].

Changed abstract to explicitly state the communication complexity that the UP batching protocol achieves.

What are the minimal cryptographic assumptions that suffice for constructing efficient argument systems, and for which tasks? Recently, Amit and Rothblum [STOC 2023] showed that one-way functions suffice for constructing constant-round arguments for bounded-depth computations. In this work we ask: what other tasks have efficient argument systems based only on one-way functions? We show two positive results:

First, we construct a new argument system for batch-verification of $k$ $UP$ statements ($NP$ statements with a unique witness) for witness relations that are verifiable in bounded depth. The communication is quasi-linear in the length of a single witness, and the number of rounds is constant. The honest prover runs in polynomial time given witnesses for all $k$ inputs' membership in the language.

Our second result is a constant-round doubly-efficient argument system for languages in $P$ that are computable by bounded-space Turing machines. For this class of computations, we obtain an exponential improvement in the trade-off between the number of rounds and the (exponent of the) communication complexity, compared to known unconditionally sound protocols [Reingold, Rothblum and Rothblum, STOC 2016].