VeriZexe: Decentralized Private Computation with Universal Setup


Alex Luoyuan Xiong, Espresso Systems, National University of Singapore; Binyi Chen and Zhenfei Zhang, Espresso Systems; Benedikt Bünz, Espresso Systems, Stanford University; Ben Fisch, Espresso Systems, Yale University; Fernando Krell and Philippe Camacho, Espresso Systems


Traditional blockchain systems execute program state transitions on-chain, requiring each network node participating in state-machine replication to re-compute every step of the program when validating transactions. This limits both scalability and privacy. Recently, Bowe et al. introduced a primitive called decentralized private computation (DPC) and provided an instantiation called Zexe, which allows users to execute arbitrary computations off-chain without revealing the program logic to the network. Moreover, transaction validation takes only constant time, independent of the off-chain computation. However, Zexe required a separate trusted setup for each application, which is highly impractical. Prior attempts to remove this per-application setup incurred significant performance loss.

We propose a new DPC instantiation VeriZexe that is highly efficient and requires only a single universal setup to support an arbitrary number of applications. Our benchmark improves the state-of-the-art by 9x in transaction generation time and by 3.4x in memory usage. Along the way, we also design efficient gadgets for variable-base multi-scalar multiplication and modular arithmetic within the Plonk constraint system, leading to a Plonk verifier gadget using only ∼ 21k Plonk constraints.

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@inproceedings {287141,
author = {Alex Luoyuan Xiong and Binyi Chen and Zhenfei Zhang and Benedikt B{\"u}nz and Ben Fisch and Fernando Krell and Philippe Camacho},
title = {{VeriZexe}: Decentralized Private Computation with Universal Setup},
booktitle = {32nd USENIX Security Symposium (USENIX Security 23)},
year = {2023},
isbn = {978-1-939133-37-3},
address = {Anaheim, CA},
pages = {4445--4462},
url = {},
publisher = {USENIX Association},
month = aug

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