Pianist: distributed zkSNARKs
Yupeng Zhang
Abstract:
In the past decade, blockchains have seen various financial and technological innovations, with cryptocurrencies reaching a market cap of over 1 trillion dollars. However, scalability is one of the key issues hindering the deployment of blockchains in many applications. To improve the throughput of the transactions, zkRollups and zkEVM techniques using the cryptographic primitive of zero-knowledge proofs (ZKPs) have been proposed and many companies are adopting these technologies in the layer-2 solutions. However, in these technologies, the proof generation of the ZKP is the bottleneck and the companies have to deploy powerful machines with TBs of memory to batch a large number of transactions in a ZKP.
In this talk, I will present our recent work, Pianist: Scalable zkRollups via Fully Distributed Zero-Knowledge Proofs, published at IEEE S&P 2024. It improves the scalability of these techniques with distributed zkSNARKs. Pianist can improve the efficiency and the scalability of zkSNARKs using multiple machines, while the communication among the machines is minimal. The protocol is based on Plonk, an efficient zero-knowledge proof system with a universal trusted setup. With 64 machines, the prover time is 48 times faster than the original Plonk on a single machine, and Pianist can scale to circuits that are 64 times larger. Moreover, the protocol incurs only O(1) communication per machine, and both the proof size and the verifier time are O(1). I will also discuss some of our recent progress on memory-efficient zkSNARKs and collaborative ZK.
Paper link: https://eprint.iacr.org/2023/1271
Bio:
Yupeng Zhang is an assistant professor at the University of Illinois Urbana-Champaign, in Electrical and Computer Engineering and Computer Science (affiliate). His research is in the area of cybersecurity and applied cryptography. Recently, he is working on zero-knowledge proofs, secure multiparty computations and their applications in blockchain and machine learning to enhance privacy, fairness and scalability.