Ethereum co-founder Vitalik Buterin would like to see a zero-knowledge Ethereum Virtual Machine (zk-EVM) built on Ethereum’s first layer to speed up the verification process on the underlying blockchain.
In a March 31 post, Buterin explained that zk-EVM could be integrated on top of the base layer without compromising decentralization and security. The technology enables the Ethereum Virtual Machine to execute smart contracts on the blockchain using ZK proofs. Buterin explained that ethereum was developed according to a "multi-client philosophy" to ensure decentralization at the protocol level. By integrating zk-EVM at Ethereum layer 1, it will become a third type of client.
"Once this happens, the zk-EVM effectively becomes a third type of Ethereum client, as important to the security of the network as execution clients and consensus clients are today."
The other two clients are the "consensus" and "execution" clients. Consensus clients implement proof-of-stake to ensure nodes in the network agree, while execution clients listen for new transactions broadcast to the network, execute them in a standard EVM and hold a copy of the latest state of the blockchain.
In backing the idea of zk-EVM proofs for Ethereum’s base layer, Buterin first considered the advantages and disadvantages of treating layer 1 as a “clearing house” by pushing almost all activity to layer 2. Many layer-1-based applications will become "economically unviable," he said, and small funds worth a few hundred dollars or less could "get stuck" if gas fees grow too large.
Buterin explained that zk-EVM needs to be “open” because different clients each have a different implementation of zk-EVM, and each client waits for a proof of compatibility with its own implementation before accepting a block as valid .
He prefers this approach because it does not abandon the "multi-client" paradigm, and the open zk-EVM infrastructure will also ensure that new clients can be developed, which will further decentralize Ethereum at the base layer. Buterin said zkEVM could be the solution to “The Verge,” part of ethereum’s roadmap to simplify verification at the base layer. Buterin acknowledged that a zk-EVM infrastructure could lead to data inefficiencies and latency issues, however, he said these challenges would not be "too difficult" to overcome.
If the zk-EVM ecosystem is implemented, it will make it easier to run a full node on ethereum, Buterin explained:
"Ethereum blocks will be smaller than today, anyone can run a fully validating node on their laptop or even their phone or browser extension, and it will all happen while retaining the benefits of the multi-client idea of Ethereum .”
Ethereum layer 2 scaling platform Polygon has made considerable progress with its zk-EVM, most recently open-sourcing its zkEVM to the Polygon mainnet on March 27, promising lower transaction costs and improved throughput for smart contract deployments. StarkWare, ConsenSys, Scroll, zkSync, and Immutable are also deploying similar zkEVM scaling solutions.
