全览零知识证明赛道：基础设施、网络及应用程序

Original author:Jonathan King

Original compilation: Deep Chao TechFlow

Zero-knowledge proof (ZKP) technology has become a major breakthrough in the field of cryptography. This article will delve into the core principles, practical applications of zero-knowledge proof technology, and its impact on blockchain scalability, privacy-preserving applications, and trustless interoperability. As investment in this technology continues to increase in 2023, zero-knowledge proofs have not only developed in theory, but also demonstrated its broad application prospects in practice. We will conduct an in-depth analysis of the zero-knowledge proof ecosystem from three levels: infrastructure, network and application, and reveal how it opens a new era of blockchain technology.

Summary

• Zero-knowledge proof (ZKP) and its derivative technologies are a major breakthrough in cryptography and are largely regarded as the ultimate goal of the blockchain design concept.

• Today, zero-knowledge proofs are increasingly emerging as a promising solution to unsolved problems in web3, including blockchain scalability, privacy-preserving applications, and trustless interoperability.

• In 2023, more than $400 million will be invested in zero-knowledge technology, mainly focused on the scalability of the Ethereum L1/L2 protocol layer, emerging infrastructure and developer tools

• The zero-knowledge field can be divided into three levels:

1) Infrastructure, i.e. tools/hardware for building protocols/applications on top of zero-knowledge primitives

2) Network, that is, L1/L2 protocol using zero-knowledge proof system

3) Applications, i.e. end-user products that utilize zero-knowledge mechanisms

Although the zero-knowledge ecosystem is still in its infancy, its rapid development promises to usher in a new era of secure, private, and scalable blockchain solutions.

introduce

Zero-knowledge proofs (ZKPs) and their derivative technologies are largely seen as the ultimate goal of blockchain design, specifically providing solutions that require little trust assumption when validating information for on-chain applications. At its core, zero-knowledge proof is a cryptographic technique that allows one party (i.e., the prover) to show another party (i.e., the verifier) ​​that a computation is valid without exposing any of the underlying data used to create the computation. Originating in 1985, zero-knowledge proofs have evolved from theory to practical applications, overcoming decades of lag through recent advances in software tools and hardware.

Today, zero-knowledge proofs offer promising solutions to Web3’s biggest challenges, including:

• Blockchain Scalability: One of the biggest challenges facing Ethereum L1 is scalability. However, the advent of L2 networks makes transactions faster and cheaper without compromising Ethereum’s security or decentralization. While optimistic rollup maintains its dominance due to its high compatibility with EVM and developer-friendliness, ZK rollup adoption is steadily increasing. Zero-knowledge proofs help summarize complex calculations off-chain, thereby enhancing L2 designs for fast and efficient on-chain verification and settlement.

• Privacy-preserving applications: To date, work on privacy in blockchain has been largely limited to hiding transactions. However, researchers are gradually working towards achieving complete transaction anonymity and confidentiality on public blockchains. Importantly, novel privacy protection concepts leveraging ZKP are emerging that aim to break the trade-off between protecting user privacy and achieving compliance (i.e., blocking illegal activities).

• Trustless interoperability: Existing blockchain interoperability protocols rely on trusted systems (e.g., multisig or incentivized validator sets). Zero-knowledge proofs can help replace cryptoeconomic trust assumptions with cryptographic guarantees, opening the way to more secure and robust cross-chain communications. However, among the main applications of ZKP, interoperability is the most emerging.

According to data from Messari, more than $400 million will be invested in the zero-knowledge proof field in 2023, emphasizing the scalability of Ethereum’s L1/L2 layer and the emerging zero-knowledge proof developer infrastructure. Although zero-knowledge proofs are relatively new, their rapidly growing ecosystem heralds a convergence of best practices for more secure, private, and scalable blockchain applications. With this framework in mind, let’s take a closer look at the world of layered zero-knowledge proofs, exploring the key players and emerging concepts.

infrastructure

Any form of zero-knowledge proof must be written in the language of arithmetic circuits, which has limited expressive capabilities and is very complex to convert most blockchain functions into circuit form. The limitations of developer tools and advanced hardware mean that practical use cases for zero-knowledge have only recently begun to develop. Today, we are seeing the emergence of a range of systems and tools that enable developers to build protocols and applications on top of zero-knowledge cryptographic infrastructure.

Programming frameworks and tools: Domain-specific languages ​​(DSLs), such as Leo, Noir, Cairo, and o1.js, are used to develop provable software in specific L1/L2 ecosystems (e.g., Aleo, Aztec, Starkware, and Mina, respectively) A programming framework for zero-knowledge programs. Additionally, general frameworks such as Elusiv and Hinkal are emerging with the aim of allowing developers to define specific criteria so that transaction data can be masked on-chain but verified using zero-knowledge proofs. The adoption of these frameworks is expected to continue to increase as demand from potential developers and end users for zero-knowledge-driven applications grows.

Zero-knowledge coprocessor: Zero-knowledge coprocessor provides developers with cost-effective and trustless off-chain computing capabilities while eliminating the need for developers to deal with complex zero-knowledge related components in the technology stack. Teams like RiscZero, Axiom, and Herodotus provide verifiable computing platforms that generate proofs to prove the execution and validity of arbitrary programs, or enable smart contracts to store, access, and verify historical on-chain data without adding additional trust assumptions . Over time, zero-knowledge coprocessors are expected to become a necessity for increasingly advanced on-chain applications.

Proof Networks/Markets: Today, most zero-knowledge networks and protocols rely on a centralized proof process. As zero-knowledge adoption gradually grows, we expect teams will look to decentralize their proof layers to increase their liveness and censorship resistance. Emerging proof networks and marketplaces such as =nil; Foundation, RiscZero, Gevulot, and Lumoz offer services designed to allow applications to outsource their proof mechanisms to third-party operators, thereby reducing the overhead of operating a zero-knowledge proof infrastructure.

Hardware acceleration: Since generating zero-knowledge proofs requires a lot of math, it is costly and computationally intensive. However, we are seeing significant progress in the use of specialized hardware such as field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs) that help improve proof generation and verification times. Specialized hardware providers such as Ingonyama, Cysic and Fabric are at the forefront of providing FPGAs and ASICs for ZK proof systems, and we expect innovation and investment in ZK hardware designs to continue to increase in the future.

Application chain infrastructure: Rollup-as-a-Service (RaaS) providers such as Spire, ProtoKit, and Lumoz provide developers with low-code tools for building, testing, and deploying general or specific applications that leverage zero-knowledge proof mechanisms. The L2/L3 chain of the application. Sequencers like Espresso, Radius, and Madara provide the infrastructure to accept user transactions, determine their order, and publish blocks to the L1 consensus and data availability layer. We believe that the next generation of Ethereum scalability will be driven by modular L2 rollup stacks, which will likely create demand for these providers in the short to medium term.

Interoperability and bridging: bridging systems become more trust-minimized as reliance on humans (such as multi-signatures or incentivized validator sets) is reduced and replaced with code (such as light clients, relays, and zero-knowledge proofs) trust. Teams like Polyhedra, Lambda Class, and Polymer Labs are exploring this topic. Among the major applications of zero-knowledge proofs, interoperability is the most emerging, but as access to zero-knowledge facilities accelerates, we expect to see more innovation in bridging design concepts.

Zero-knowledge machine learning (ZKML): ZKML is a cutting-edge field in cryptography focused on using zero-knowledge proofs to prove the correctness of on-chain machine learning (ML) model inferences. By adding ML capabilities, smart contracts can become more autonomous and dynamic, allowing them to make decisions based on real-time on-chain data and adapt to a variety of scenarios, including ones that may not have been anticipated when the contract was originally created. Teams like Modulus Labs, Giza, and Zama are pioneering unique ZKML use cases that may provide a promising synergistic balance at the intersection of AI and cryptography.

network

Some blockchains face limitations in handling high transaction volumes, resulting in slower transaction times and increased costs during peak demand periods. Additionally, popular blockchains like Bitcoin, Ethereum, and Solana are built on open public ledgers, but the lack of privacy raises concerns among mainstream players about complete transaction confidentiality and anonymity. New L1 and L2 networks are emerging that employ zero-knowledge proof infrastructure to solve issues related to blockchain scalability and on-chain privacy.

Privacy-focused L1: Emerging L1 networks like Aleo, Mina, and IronFish provide privacy-first smart contract capabilities based on zero-knowledge proofs to provide application-level privacy for decentralized applications within their respective ecosystems. L1 networks like Fhenix and Inco employ fully homomorphic encryption (FHE), enabling developers to write private smart contracts and perform computations on top of encrypted data, achieving complete transaction anonymity and confidentiality. Given that many of the aforementioned L1s are running incentivized testnets and require developers to learn new programming languages, signs of mass adoption and value capture may take 1-2 years.

ZK-EVM: ZK-EVM utilizes zero-knowledge proofs to cryptographically prove the execution of Ethereum-like transactions. Different types of ZK-EVM such as zkSync Era, Polygon zkEVM, Linea, Scroll and Taiko have different design trade-offs between EVM compatibility and performance (i.e. proof build time). We expect continued innovation in this space to scale Ethereum and Ethereum-based ZK rollups.

ZK-Rollup: Zero-knowledge rollup is an L2 scaling solution that moves computation off-chain and uses zero-knowledge proofs to prove state changes on-chain. ZK-rollups like Aztec provide a privacy engine on top of Ethereum designed to encrypt transaction data while ensuring costs remain low. Zeko is an upcoming ZK-rollup stack built on Mina that enables applications to recursively validate and compose with each other, while ImmutableX and LayerN are application-specific ZK rollups targeting gaming and high-performance DeFi use cases respectively. While optimistic-based rollups account for approximately 90% of the total L2 market share, the demand for ZK-rollups is expected to increase as the underlying technology becomes more accessible.

application

On top of the ZK infrastructure and network layer, a number of end-user applications have emerged that leverage zero-knowledge proofs for on-chain payments, identity verification, private but compliant DeFi and consumer use cases.

Teams like Elusiv provide user-friendly interfaces for private payments and DeFi transactions, and do so by masking addresses, while employing compliance mechanisms to decrypt transactions from identified illegal actors. When it comes to authentication, zCloak, ZKPass, and zkp-ID use zero-knowledge proofs to let users prove verifiable data to third parties without exposing personal information.

DeFi protocols like Lumina and Panther focus on building private yet compliant decentralized exchanges. Renegade combines multi-party computation (MPC) and ZK technology to offer dark pool trading, an on-chain trading venue that hides the order book and allows large institutions or high-volume traders to trade without exposing their activities to the wider market. Place an execution order.

Consumer applications like Sealcaster and Dark Forest leverage zero-knowledge proofs in social and gaming applications to shield user identities and gaming strategies from other on-chain participants.

The future of ZK

The future of ZK involves prioritizing speed, reducing hardware requirements, improving development tools, and supporting new zero-knowledge proof designs that support decentralized proof generation. While both Optimistic and zero-knowledge scaling solutions are used to verify rollup transactions, each has associated design tradeoffs in terms of security, latency, and computational efficiency. We see these two technology stacks converging in the medium to long term to accommodate a diverse range of on-chain applications. Finally, the zero-knowledge application layer is in its infancy today but is expected to grow in the future as end-user demand for privacy protection on public blockchains grows. Furthermore, it is worth noting that zero-knowledge research has been primarily explored in the context of Ethereum. However, emerging concepts like Solana’s Token 22 initiative with Confidential Transfers, a privacy feature that utilizes zero-knowledge proofs to encrypt SPL token balances and transfer amounts, demonstrate the adaptability and potential of zero-knowledge beyond specific ecosystems.

In summary, the transformative potential of zero-knowledge is unfolding, signaling a future where blockchain solutions will be even more significant in terms of security, privacy, and scalability.

Note: Projects invested by Coinbase Ventures appear in the above zero-knowledge proof track: Aleo, Anoma, Aztec, Consensys, Espresso, Elusiv, Mina, Polygon, Polymer Labs, Starkware, Sunscreen, zCloak, zkLink, zkSync