Introducing Hermez zkEVM

4 months ago   •   2 min read

By Polygon Hermez

If you’ve been paying attention to the news from the EthCC 4, this article won’t take you by surprise: the Hermez zero-knowledge Ethereum Virtual Machine (zkEVM) is in the works!

We’re delighted to share this with the Ethereum community, as it marks a new phase in the collective efforts that many teams are making to scale Ethereum infrastructure.

In this article, you’ll find the reasons behind the Hermez zkEVM and an outline of the roadmap to get it done. Let’s jump right in!

Jordi Baylina’s Talk at EthCC 4

On Thursday 22nd of July, Hermez’s Technical Lead, Jordi Baylina, announced to the EthCC attendees that the team is working to develop a zkEVM.

During a 45 minute presentation, Jordi walked a full room of attendees through some of the math behind the Hermez zkEVM, with the word “polynomials” making the journey presentation-to-meme in record time.

If you missed it, you can watch it here. The last few minutes of the video are a great session of Q&A that are as interesting as the presentation itself.

If you want to browse through the presentation slides, you can do so here.

Hermez zkEVM TL;DR

The Ethereum Virtual Machine (EVM) was not designed to run in a zk-circuit, and to achieve this, three different strategies have been presented so far:

  • Virtual machine optimised for zero-knowledge, which equates to starting a new blockchain from scratch.
  • EVM-compatible, which also starts from scratch and adapts the current tooling to the new virtual machine.
  • Hermez zkEVM: Implementing OPCODE full compatibility.

Full compatibility with Opcodes has inherent advantages and technical features:

  • uVM: A zkCircuit optimised VM with tailor made opcodes to optimise the EVM interpretation.
  • Easy to implement variable EVM opcodes: CALL, DATACOPY, EXP, CREATE, etc.
  • Multi StateMachine architecture to implement difficult opcodes like MULMOD, EXP or even pairings.
  • Fixed uVM assembly code to process all transactions of a block fetching and interpreting all the opcodes.
Inputs: OldState & List of TXs to process
Output: New State

The Hermez team believes that the OPCODE-based approach is the needed solution. Efficiency should be similar to a compiler-based approach, and it will inherit Ethereum’s security model.

Even more importantly, it will be fully compatible with all infrastructure, as specifications of the EVM are very well defined.

The Road to Mainnet

The Hermez zkEVM is perhaps the most ambitious development that the team is working on and, as Jordi said during the presentation, we don’t want to be constrained by a hard roadmap.

Here’s an estimated timeline of the zkEVM development:

Again, this should be taken as an estimation, not a commitment, as this is a whole new technology and unexpected delays or challenges might arise.

If you want to know more about the current status of Hermez development, you can watch the interview that Bankless did with Jordi at EthCC.

What are your thoughts on the Hermez zkEVM?

Let us know by commenting on Discord. You can also join the conversation on Twitter and Telegram.

Spread the word

Keep reading