Zero-Knowledge Proofs and Zero-Knowledge EVMs

In this chapter, we’ll take a beginner-friendly dive into some advanced topics – Zero-Knowledge Proofs (ZKPs) and Zero-Knowledge EVMs (ZKEVMs). We’ll introduce you to these concepts, explore where they can be useful, and understand their vital role in the future of Ethereum technology. Here’s what we’ll focus on:

• Understanding ZKPs
• Understanding ZKEVMs

This chapter will set the stage for your journey into these intriguing concepts.

A classic example of a ZKP is the “Ali Baba’s cave” analogy. In this scenario, the prover wants to convince the verifier that they know the secret password to open a door inside a cave without revealing the password itself. They do this by entering the cave through the door while the verifier is not looking, and then exiting the cave through another entrance. The verifier can be convinced that the prover knows the password, since they...

Exploring ZKPs and their integration with the Ethereum Virtual Machine

ZKPs are cryptographic techniques that enable one party to prove the validity of a statement without revealing any information beyond the statement’s truth. They play a crucial role in enhancing privacy and security in various applications, including blockchain technology.

ZKPs allow users to prove the correctness of their actions, such as transactions or smart contract executions, without disclosing the underlying data or details. This ensures privacy and confidentiality, which is particularly valuable in public blockchains where transaction data is visible to all participants.

In the world of blockchain and smart contracts, there's a new technology called zkEVM that's being added to Ethereum's "brain," known as the Ethereum Virtual Machine (EVM). The EVM acts like the engine that powers smart contracts on Ethereum, making things work in decentralized apps (dApps). However...

Understanding ZKPs

ZKPs are like a magic trick in cryptography. They let one person prove to another that they know something or that something is true, without actually revealing what that thing is or any extra details about it. It’s a way to share secrets without giving away the whole story. This concept is essential in preserving privacy in various cryptographic applications, as it enables secure authentication and verification without disclosing sensitive information.

A ZKP has three main properties:

• Completeness: If the statement is true and both the prover and verifier follow the protocol, the verifier will be convinced that the statement is true.
• Soundness: If the statement is false, a dishonest prover cannot convince the verifier that the statement is true, except with negligible probability.
• Zero-knowledge: If the statement is true, the verifier learns nothing beyond the fact that the statement is true. In other words, the verifier cannot extract...

Understanding the zkEVM

zkEVM is an implementation of the EVM that leverages ZKPs to enable privacy-preserving smart contracts and computations on the Ethereum blockchain.

The EVM is the runtime environment for smart contracts on the Ethereum network. It is a Turing-complete virtual machine that processes and executes smart contract code, making it possible to build and deploy dApps on Ethereum. However, one of the limitations of the current EVM is the lack of native support for privacy-preserving computations and transactions.

The zkEVM aims to address this limitation by integrating ZKPs into the EVM, allowing users to create and interact with smart contracts while keeping their input, output, and state changes private. In a zkEVM, users can prove the correctness of their smart contract executions without revealing the underlying data, thus ensuring privacy and confidentiality.

Integrating ZKPs into the EVM has several potential benefits and use cases:

• Privacy-preserving...

Summary

In this chapter, we delved into the world of ZKPs and their wide-ranging applications in cryptography, blockchain technology, and smart contracts. Here are the key takeaways.

We discussed the fundamental concept of ZKPs, which allows one party to prove a statement’s validity without revealing any additional information, enhancing privacy and security.

We explored how ZKPs are integral to privacy-focused cryptocurrencies such as Zcash and Monero, as well as Layer 2 scaling solutions such as zkSync, which leverage zk-Rollups to enhance transaction throughput and reduce gas fees on Ethereum.

Then, we introduced the concept of the zkEVM, highlighting how ZKPs can enable privacy-preserving smart contracts and computations, revolutionizing blockchain technology.

Although various zkEVM types exist, there is not a widely accepted classification system yet. Nevertheless, numerous projects and researchers are actively working on implementing ZKPs in Ethereum and creating...