Succinct Scriptable NIZK via Trusted Hardware

Abstract

Non-interactive zero-knowledge proof or argument (NIZK) systems are widely used in many security sensitive applications to enhance computation integrity, privacy and scalability. In such systems, a prover wants to convince one or more verifiers that the result of a public function is correctly computed without revealing the (potential) private input, such as the witness. In this work, we introduce a new notion, called succinct scriptable NIZK, where the prover and verifier(s) can specify the function (or language instance) to be proven via a script. We formalize this notion is UC framework and provide a generic trusted hardware based solution. We then instantiate our solution in both SGX and Trustzone with Lua script engine. The system can be easily used by typical programmers without any cryptographic background. The benchmark result shows that our solution is better than all the known NIZK proof systems w.r.t. prover’s running time (1000 times faster), verifier’s running time, and the proof size. Finally, we show how the proposed scriptable succinct NIZK can be readily deployed to solve many well-known problems in the blockchain context, e.g. verifier’s dilemma, fast joining for new players, etc..