Polygon Releases 'Type 1 Prover,' Claiming Milestone Set by Ethereum's Vitalik Buterin

• The "Type 1 prover" has been cast as a technological feat that essentially makes layer-2 networks nearly equivalent to main "layer-1" blockchains like Ethereum.
• Polygon is betting that more networks will use the new prover to connect to its own blockchain ecosystem.
• Polygon had previously relied on a "Type 2" prover that doesn't provide the same level of Ethereum equivalence.

Polygon Labs, the developer behind the Polygon blockchain, released Thursday a "Type 1 prover," a new component allowing any network compatible with Ethereum's EVM standard to become a layer-2 network powered by zero-knowledge proofs, and to connect to Polygon’s broader ecosystem.

The Polygon team claimed the release as a major breakthrough, a technological feat that even Ethereum co-founder Vitalik Buterin has touted as key to making auxiliary layer-2 networks nearly equivalent to the base blockchain.

The Type 1 prover comes as Polygon pursues its Polygon 2.0 roadmap, with a focus on making its ecosystem more interconnected, with big bets on "zero-knowledge" or ZK cryptography as a core technology.

At a high level, the announcement means that existing EVM chains or optimistic rollups can connect to the prover without modification, then plug into Polygon’s newly released Aggregation layer, providing access to "all of the liquidity and value on Ethereum itself,” according to Polygon’s blog post seen by CoinDesk.

Polygon currently uses a Type 2 prover, which means it isn't fully equivalent to the functionality that exists on the main Ethereum blockchain.

The blog post also said that the type 1 prover will be able to generate these ZK proofs for Ethereum mainnet blocks, with an average cost of $0.002-$0.003 per transaction.

The Type 1 prover is open-sourced and is available on GitHub, with licenses obtained from MIT and Apache 2.0.

Vitalik Buterin, the co-founder of the Ethereum blockchain, has previously written about the different types of provers, arguing that the benefit a Type 1 prover is that it is perfectly compatible with Ethereum, while the disadvantage is that there’s a lot of computation power that goes into producing ZK-proofs that are compatible with Ethereum, taking up to hours to produce.

“Delivering a performant Type 1 zkEVM was seen as impractical and cost-prohibitive,” said Brendan Farmer, a co-founder of Polygon, in an email to CoinDesk. “Polygon has again demonstrated that it leads the industry in the development of ZK technology by delivering a Type 1 zkEVM that is insanely efficient.”

Read more: Polygon Plans 'AggLayer,' in Bid to Synthesize Modular, Monolithic Blockchains