What is ZK Rollup? An analysis of the most promising Layer 2 scaling solution for Ethereum in 2025

What is ZK Rollup? Core Concepts and How It Works

When we discuss “what is zk rollup,” the first thing to understand is that it is a revolutionary blockchain scaling technology. ZK Rollup is essentially an Ethereum Layer 2 solution that processes a large number of transactions off-chain, then verifies their validity using zero-knowledge proofs, thereby significantly increasing network throughput while maintaining security.

As the leading smart contract platform globally, Ethereum has achieved remarkable success in DeFi and NFT sectors but also exposed a critical weakness—high gas fees caused by transaction congestion. Although Ethereum 2.0 upgrades are still underway, a faster and more efficient solution is to adopt Layer 2 scaling technologies. ZK Rollup emerged in this context.

How ZK Rollup Works

Understanding “what is zk rollup” hinges on grasping its technical architecture. The solution consists of two core components:

On-chain smart contract layer: Contracts on the mainnet define transaction rules and store key data states.

Off-chain virtual machine processing layer: Executes a large volume of transactions in isolated virtual environments, significantly reducing costs and latency.

Zero-knowledge proof generation: The system creates cryptographic proofs to verify the validity of the entire batch of transactions without revealing any details of individual transactions.

Mainnet verification and confirmation: This compact proof is submitted to the Ethereum mainnet, where validators confirm its correctness.

ZK Rollup employs a clever zero-knowledge proof technology (Zero-Knowledge Proofs, ZKP), allowing the system to prove the legitimacy of a batch of transactions without exposing transaction details. These proofs have three key properties: completeness, soundness, and zero-knowledge, collectively ensuring transaction security and privacy.

Why ZK Rollup Is Superior to Other Layer 2 Solutions

In the discussion of “what is zk rollup,” it is necessary to compare it with competing solutions. Compared to Optimistic Rollup and other Layer 2 options, ZK Rollup has clear advantages:

Transaction finality: Optimistic Rollup assumes transactions are valid by default and only verifies during disputes; ZK Rollup verifies each transaction with zero-knowledge proofs. This means ZK Rollup can achieve instant finality, whereas Optimistic Rollup requires waiting for a challenge period (usually 7 days).

Trust model: ZK Rollup does not rely on any trusted third parties, ensuring security purely through cryptography; Optimistic Rollup implicitly assumes honest validators.

Privacy protection: ZK Rollup natively supports higher levels of privacy—transaction details are encapsulated within proofs; Optimistic Rollup is relatively transparent.

Technical complexity: The cryptographic foundation of ZK Rollup makes it more difficult to implement, but it also provides stronger security guarantees.

Top ZK Rollup Projects to Watch in 2025

Manta Network—Leader in Privacy DeFi

Circulating Market Cap: $34.02M
Mainnet Launch: September 2023
Native Token: MANTA

Manta Pacific, as Manta Network’s Layer 2 implementation on Ethereum, uses zk-SNARKs technology architecture. Since its launch, its TVL has grown rapidly, becoming the fourth-largest participant in Ethereum’s Layer 2 ecosystem, even surpassing Coinbase’s Base.

What makes this project unique is its focus on privacy protection as a core feature of DeFi applications. Users can perform token swaps and asset transfers in fully private environments, with transaction details—including asset types and amounts—encrypted, yet still verifiable for legitimacy. This functionality is rare among DeFi platforms and provides strong support for institutional investors and privacy-conscious users.

Manta Network also aims to provide privacy layers for cross-chain DeFi applications, with ambitious plans.

Linea—A User-Friendly High-Performance Solution

Circulating Market Cap: $107.82M
Mainnet Launch: August 2023
Native Token: LINEA

Linea, developed by ConsenSys, is a ZK Rollup extension that uses zk-SNARKs for transaction verification. Its workflow involves processing transactions off-chain, grouping them, and then generating a single zk-SNARK proof to submit to Ethereum mainnet.

The project emphasizes developer friendliness, aiming to make migrating DApps to Linea quick and easy. In January 2024, Linea announced a native token airdrop, further boosting community engagement. Its core strengths are excellent scalability and significantly reduced transaction costs.

Starknet—Future-Proofing with Quantum Resistance

Circulating Market Cap: $397.42M
Mainnet Launch: February 2022
Platform Token: STRK

Starknet is based on STARKs technology (Scalable Transparent ARguments of Knowledge), a different zero-knowledge proof method from SNARKs. The key advantage of STARKs is that they do not require trusted setup and are inherently resistant to quantum computing threats—crucial for long-term blockchain security.

The platform supports general-purpose computing, allowing arbitrary smart contracts to run, providing high flexibility for developers. Starknet achieves significant scalability and privacy protection by processing and verifying transactions off-chain, generating proofs with STARKs, and submitting them to the mainnet.

zkSync Era—Most Compatible Solution

Circulating Market Cap: $555M (based on ZKS token valuation)
Mainnet Launch: March 2023
Platform Token: ZKS

Developed by Matter Labs, zkSync Era is currently the largest ZK Rollup solution by TVL. It uses zkRollup technology, emphasizing user experience and Ethereum compatibility.

Its operation involves batching transactions off-chain, generating a single zero-knowledge proof, and submitting it to the mainnet. Its biggest selling point is full EVM compatibility—existing Ethereum smart contracts can be deployed and run without modifications. This is a huge advantage for developers seeking easy migration.

Scroll—Pursuer of Extreme Performance

Circulating Market Cap: Unreleased native token
Network Launch: October 2023
Technical Basis: zk-SNARKs

Scroll focuses on achieving maximum throughput and minimal latency. It aggregates transactions executed off-chain into a single zk-SNARK proof, which is then submitted to Ethereum.

The project emphasizes EVM compatibility, allowing existing Ethereum dApps to migrate easily. Scroll aims to be the optimal solution for high-capacity transaction scenarios, especially DeFi, attracting users and developers with low costs and high efficiency.

Polygon zkEVM—A Model of Ecosystem Integration

Technical Architecture: ZK Rollup solution
Mainnet Launch: March 2023 (test phase)
Platform Token: MATIC

As a key part of the Polygon ecosystem, zkEVM implements ZK Rollup on Polygon’s existing infrastructure. It executes transactions off-chain within an EVM-compatible environment, then verifies their legitimacy with ZK proofs.

This solution’s advantage lies in deep integration with the Polygon ecosystem, enabling broader network effects. Its full compatibility with existing Ethereum tools and contracts allows developers to migrate applications at minimal cost.

Aztec Protocol—Innovator in Privacy Computing

Launch Date: 2017
Native Token: None yet
Technical Features: Hybrid public-private execution model

Aztec Protocol adopts a unique hybrid public-private ZK Rollup architecture, allowing smart contract logic to be either publicly or privately executed while maintaining Ethereum’s security guarantees. Privacy is optional, opening possibilities for private transactions and anonymous voting.

The project also introduced Noir, a programming language that greatly simplifies the development of zero-knowledge circuits, lowering the barrier for ZK application development. Aztec is committed to fully decentralized governance and censorship resistance.

ZKFair—Guardian of Fair Trading

Launch Date: December 2023
Native Token: ZKF
Market Cap: $163M

ZKFair is a decentralized exchange based on ZK Rollup technology, focused on protecting trading fairness. Its core innovation is preventing front-running—a common issue in traditional DEXs.

Using zero-knowledge proofs, ZKFair ensures transaction order integrity, preventing MEV (Maximal Extractable Value) exploitation. This makes it highly attractive to traders who prioritize fairness.

ZetaChain—Pioneer of Cross-Chain Interoperability

Circulating Market Cap: $81.08M
Launch Date: February 2021
Platform Token: ZETA

ZetaChain uses ZK Rollup technology to build a “universal cross-chain bridge,” verifying cross-chain transactions with zk-SNARKs, enabling seamless transfer of assets and data while preserving privacy.

The platform also introduces ZetaML for off-chain contract execution. ZetaChain’s core advantage is enabling DApps to easily access multi-chain assets and data without technical complexity.

Taiko—Practitioner of Decentralized Ordering

Launch Date: January 2024 (testnet)
Funding: $37M (two funding rounds)
Technical Innovation: Based ordering mechanism

Taiko employs ZK-EVM and ZK Rollup technologies to build Layer 2 solutions with full Ethereum compatibility. Its key innovation is the “based ordering” architecture—ordering rights are handled by Layer 1 block producers rather than independent entities.

This design fundamentally addresses the centralization risk of orderers in traditional Rollups, eliminating single points of failure or censorship. It also reduces trust assumptions and simplifies the value chain of Layer 2 systems.

DeGate V1—Optimizer for Derivatives Trading

Launch Date: September 2022
Platform Token: DG
Market Cap: $21.14M

DeGate V1 is built on ZK Rollup, focusing on derivatives trading scenarios. By batching off-chain transactions and verifying with zero-knowledge proofs, it offers low slippage and low-cost trading experiences.

Its main advantage is excellent performance in large-volume trades, making it especially suitable for institutional trading needs.

Limitations of ZK Rollup Technology

Despite promising prospects, ZK Rollup still faces practical challenges:

Implementation complexity: Advanced cryptographic algorithms increase development and maintenance difficulty.

Flexibility limitations: Not all transaction types can be efficiently processed within ZK frameworks.

Data availability requirements: Ensuring transaction data availability is critical; reliable management mechanisms are needed.

Proof generation efficiency: Creating cryptographic proofs can be computationally intensive, potentially becoming a bottleneck.

Market adoption difficulties: Widespread acceptance by users and ecosystems is necessary.

Governance complexity: Protocol upgrades and parameter adjustments require effective decentralized decision-making.

Economic sustainability: Balancing operational costs and fee models remains an ongoing challenge.

Outlook: The Future of ZK Rollup

Current research focuses on lowering the technical barriers of ZK Rollup and improving integration with Ethereum. Continuous innovation aims to address complexity issues and tackle liquidity fragmentation.

With steady development and industry collaboration, ZK Rollup has the potential to transform the Ethereum ecosystem, fostering a new generation of high-speed, cost-effective, and secure blockchain applications. This could mark a turning point for large-scale blockchain adoption.

Conclusion

ZK Rollup represents a significant evolution in blockchain scaling technology. By efficiently processing transactions off-chain while ensuring on-chain security, ZK Rollup points the way forward for Ethereum and the entire blockchain ecosystem. As this technology matures, it will unlock the potential for large-scale blockchain applications, bringing new possibilities for users and ecosystem participants.