Polygon's New ZK Proving System, 'Plonky3,' Comes as Open-Source Toolkit

Polygon Labs, the main developer firm behind the layer-2 blockchain Polygon, released on Tuesday the latest version of its zero-knowledge proving system, “Plonky3” – designed to be more flexible than the previous model.

A proving system is at the heart of zero-knowledge rollups, and a crucial component in the cryptographic security of distributed networks with multiple layers. It is the piece of technology responsible for creating proofs that summarize off-chain transactions, so the information can then be fed back to a base blockchain, such as Ethereum. The system ensures “that a transaction was correctly executed or that a blockchain’s state has been updated properly,” according to a press release.

Polygon Plonky3 is now available as open-source software under the popular MIT and Apache licenses, the company said.

The company's previous proving system, Plonky2, was introduced in 2022 as “a single proving system focused on lightning-fast recursion by optimizing for hardware,” Polygon wrote in the press release, whereas Polygon Plonky3 is an "open-source toolkit that empowers ZK developers to build their own" virtual machines based on ZK cryptography.

When Polygon released Plonky2 in 2022, the project's developers claimed that it was 100 times faster than existing alternatives at the time.

“Plonky2 partly had some performance issues, and partly didn't quite have the generality that we needed,” said Daniel Lubarov, a co-founder at Polygon, said in an interview with CoinDesk. “We see it as more part of the future direction of Polygon technology.”

Polygon and ZK cryptography

“The proving system is the underlying thing that kind of allows us to do that [proving] efficiently and sort of within a practical level of performance,” Brendan Farmer, a co-founder at Polygon, added in an interview.

Polygon has fully embraced zero-knowledge technology, seen as one of the hottest trends in blockchain. In 2021, Polygon acquired the Hermez and Mir teams, among the most prominent zero-knowledge cryptography teams at the time, and brought their founders in-house. Farmer and Lubarov co-founded Mir together.

Since then, Polygon was one of the first teams to launch a zero-knowledge rollup in 2023, and acquired a third firm, Toposware, to continue building out its zero-knowledge expertise.

“In the past, we had Plonky2, and we also had a few other separate prover libraries, one by the Miden group and one by the Hermez group within Polygon,” Lubarov told CoinDesk. “Our plan now is to bring it all together under one code base and one framework.”

Read more: Polygon Acquires Zero-Knowledge Cryptography Firm Toposware