ZK EVM: Revolutionizing Ethereum’s Scalability and Privacy with Zero-Knowledge Proofs
In the world of blockchain technology, the combination of zero-knowledge proofs (ZKP) and the Ethereum Virtual Machine (EVM) has given rise to an innovative solution known as ZK EVM (Zero-Knowledge Ethereum Virtual Machine). This article delves deeper into the concept of ZK EVM, its purpose, and its potential to revolutionize the scalability and privacy of the Ethereum network.
Zero-Knowledge Proofs (ZKP): Zero-knowledge proofs provide a method for one party, known as the prover, to demonstrate the truth of a statement to another party, the verifier, without disclosing any additional information apart from the validity of that specific statement. These protocols ensure privacy and security while validating information. For a comprehensive understanding of ZKP, refer to my previous article on zero-knowledge proofs in blockchain- https://medium.com/coinmonks/zero-knowledge-proofs-in-blockchain-its-implementation-and-misuse-12a8a7a1e04c
Ethereum Virtual Machine (EVM): The Ethereum Virtual Machine (EVM) is a decentralized virtual machine that executes smart contracts on the Ethereum blockchain. It is the runtime environment for Ethereum’s smart contracts and is responsible for processing transactions and executing the code of smart contracts.
- The EVM is a software-based emulation of a physical computer, similar to other virtual machines. It has its own instruction set and operates independently of the underlying hardware. The EVM is designed to be secure, deterministic, and gas-efficient.
- Smart contracts are written in high-level programming languages such as Solidity and compiled into EVM bytecode. This bytecode can then be deployed to the Ethereum network and executed by the EVM.
- When a transaction is submitted to the Ethereum network, the EVM verifies that the transaction is valid and executes the corresponding smart contract code. The EVM maintains a record of all transactions and contract states on the Ethereum blockchain.
Now, let’s delve into zkEVM :
- A zkEVM is a virtual machine that is compatible with the Ethereum Virtual Machine (EVM) and enables zero-knowledge-proof computation. Unlike traditional virtual machines, zkEVM verifies the accuracy of program execution, including the validity of inputs and outputs used in the operation.
- ZK EVM (Zero-Knowledge Ethereum Virtual Machine) is a layer 2 scaling solution designed to enhance scalability and privacy on the Ethereum network by leveraging zero-knowledge proofs.
- By utilizing zero-knowledge proofs, ZK EVM enables users to validate the correctness of a computation without revealing any input or output data.
- In the ZK EVM system, smart contracts are executed off-chain, and only the final result is stored on the Ethereum blockchain. This reduces the amount of data that needs to be stored and processed, resulting in improved scalability and reduced transaction fees.
Example:
Polygon ZK EVM :- One prominent implementation of ZK EVM is Polygon’s zkEVM. This zero-knowledge scaling solution is fully compatible with the EVM, seamlessly supporting existing smart contracts, developer tooling, and wallets. Polygon zkEVM harnesses the power of zero-knowledge proofs to reduce transaction costs and significantly increase throughput, while maintaining the security of Ethereum.
Building on Polygon zkEVM is akin to Ethereum, requiring a simple switch to the zkEVM RPC. Developers and users can experience a complete EVM-like environment, eliminating the need for specialized tools or new wallets. This compatibility facilitates the transition to a network with higher throughput and lower fees.
Let’s say if I want to execute a smart contract on the Ethereum network using ZK-EVM. Normally, this would require submitting the smart contract code and all input data to the Ethereum network for processing, which can be slow and expensive, especially if the smart contract involves complex computations.
→ With ZK-EVM,I can instead submit the smart contract code and input data to a ZK-EVM node, which will use zero-knowledge proofs to verify the correctness of the computation off-chain. Specifically, the ZK-EVM node will use a combination of cryptographic techniques to prove that the smart contract code was executed correctly and that the output is valid, without revealing any of the intermediate computation steps.
→ Once the zero-knowledge proof has been generated and verified, the ZK-EVM node will submit the transaction to the Ethereum network and the proof for final confirmation. Because the computation has already been verified off-chain, the Ethereum network only needs to validate the proof and record the transaction, rather than re-executing the entire smart contract computation.
→ This off-chain processing of smart contract computations allows for much faster transaction processing times and significantly increases the scalability of the Ethereum network.
The provided image showcases the Polygon zkEVM Bridge, which facilitates the transfer of tokens between different blockchain networks using a bridge mechanism. Here is the link for this : https://wallet.polygon.technology/zkEVM-Bridge/bridge
Now, let’s delve into the architecture of zkEVM and explore its components :
The zkEVM architecture encompasses three crucial components: the execution environment, proving circuit, and verifier contract. Each element plays a vital role in the program execution, proof generation, and verification process within zkEVM.
- Execution Environment: The execution environment within zkEVM serves as a platform where programs, such as smart contracts, are executed. Similar to the Ethereum Virtual Machine (EVM), the zkEVM’s execution environment takes the initial state and current transaction as inputs and generates a new, final state as output.
- Proving Circuit: The proving circuit is responsible for generating zero-knowledge proofs that verify the validity of transactions executed within the zkEVM’s execution environment. These proofs provide cryptographic evidence that the computations performed within the zkEVM are accurate and consistent with the specified rules and constraints.
- Verifier Contract: In the context of ZK-rollups, the verifier contract serves as a smart contract deployed on the Layer 1 chain (Ethereum). Validity proofs, along with the relevant input data such as pre-states and transaction information, are submitted to this verifier contract for verification. The verifier contract then executes the computation based on the provided proof and confirms whether the submitted outputs (final states) were correctly derived from the given inputs.
