Best ZK-Rollup Projects in 2024

ZK rollups are steadily making their mark in Ethereum scaling. Using zero-knowledge proofs, these projects process transactions off-chain, achieving speed, security, and cost efficiency that’s catching up to major optimistic rollups like Arbitrum, Optimism, and Base.

Though optimistic rollups lead the market, ZK rollups are setting themselves apart in DeFi by offering faster finality, reduced transaction fees, and stronger data privacy.

Here’s a breakdown of 2024’s top ZK rollups and the features that make each project distinct:

1. Linea (LXP)

Linea is the leading Ethereum ZK rollup blockchain, with the highest total value locked (TVL) at $478 million, despite not yet having its own token. Using zkEVM technology, Linea offers fast transaction finalization, strong security, and full EVM compatibility, making it easy for developers to migrate projects.

The Linea layer 2 enables developers to deploy new or existing Ethereum applications without code modification, ensuring high accessibility. To reward community engagement, Linea also plans an airdrop through the Linea Voyage LXP points program.

Linea’s architecture includes three main components: the Sequencer, which processes and batches transactions; the Prover, which creates zero-knowledge proofs for transaction validation; and the Bridge Relayer, which enables data transfer between Linea and networks like Ethereum Mainnet.

2. ZKsync Era (ZK)

ZKsync Era is among the most talked-about ZK rollup projects of 2024, with its recent ZK token airdrop triggering controversy across the decentralized space. Hosting 117 decentralized protocols, ZKsync has decentralized exchanges leading in activity and value.

A few months after its release, the ZK token reached a market cap of $515 million, placing it among the top 150 tokens. With a total value locked at barely $85 million, the platform has dropped profoundly against its ZK rollup competitors.

ZKsync optimizes scalability and efficiency by supporting nearly all Ethereum Virtual Machine (EVM) smart contracts. Its architecture, optimized for smart contract handling and memory management, delivers greater scalability than traditional Ethereum and previous ZKsync versions.

3. Starknet (STRK)

Starknet ranks mid-list among ZK rollup projects, facing mixed reviews, especially after user numbers fell sharply following its STRK airdrop. Despite a decline from 300,000 to just 7,100 active users, Starknet holds a market cap of $749 million and a TVL of $249 million.

Starknet stands out with its privacy-first approach, using a proprietary STARK proof system to verify transactions while protecting sensitive data. In addition, Cairo, a custom-built and specialized programming language, is used to write Starknet contracts and the Starknet OS.

Starknet's architecture features smart contract-based user accounts for flexibility and superior wallet recovery, a Sequencer for transaction management, a Prover for cryptographic proof generation, full nodes for record-keeping, and a Verifier for proof validation and state updates.

4. Polygon zkEVM (MATIC)

Polygon zkEVM, launched in 2017, recently rebranded to establish itself as a top blockchain aggregator. The project now supports an infinitely scalable network of connected blockchains powered by Zero-Knowledge technology.

In September 2024, Polygon began transitioning its MATIC token to POL and currently has a market cap of $3.5 billion ($2.6 billion in POL and $0.9 billion in MATIC). With a TVL of $1 billion, Polygon is the third largest layer 2 network on Ethereum.

Polygon’s ZK rollups each bring distinct innovations: Hermez optimizes ZK proofs and batching with 'Proof of Efficiency'; Nightfall combines optimistic rollups and zero-knowledge for private transactions; and Miden, a STARK-based rollup, boosts scalability by executing smart contracts locally.

5. Scroll

Scroll was one of the most anticipated ZK rollup layer 2 projects in 2024, with a current TVL of $471 million. Its developer-centric approach supports an impressive ecosystem of 85 protocols, specializing in yield farming, lending, and liquid restaking.

What makes Scroll unique is its three-part architecture, featuring a Settlement Layer for secure data availability, a Sequencing Layer for efficient transaction batching, and a Proving Layer for zkEVM validity proofs. This design ensures high scalability, fast finality, and full interoperability with Ethereum.

The Scroll governance token (SCR) debuted in October 2024, facing a big backlash as it launched 5.5% of its supply through Binance’s Launchpool program rather than prioritizing early adopters. This decision, along with a low circulating supply, led to SCR crashing by 60%.

What is a Zero Knowledge (ZK) Rollup?

A ZK Rollup is a layer 2 network that uses zero-knowledge (ZK) proofs to bundle multiple transactions and process them off-chain, strenghtening the scalability and efficiency of blockchain networks like Ethereum.

In a ZK Rollup, cryptographic proofs verify the validity of transactions without revealing sensitive information, ensuring both privacy and security. By reducing the amount of data posted directly on the main blockchain, ZK Rollups radically lower transaction costs and increase throughput.

What is a zkEVM Rollup?

A zkEVM Rollup is a type of zero-knowledge (ZK) rollup designed to be fully compatible with the Ethereum Virtual Machine (EVM), allowing it to run Ethereum-based smart contracts.

By maintaining EVM compatibility (and sometimes EVM Equivalence), zkEVM rollups enable developers to deploy Ethereum applications directly on layer 2 with minimal modification.

Challenges and Limitations of Zero Knowledge Rollups

Zero-knowledge rollups face challenges in both complexity and computational demand, making them difficult to implement and resource-intensive.

1. Base Layer Limitations: ZK rollups are constrained by the underlying blockchain's blockspace, which can be costly and limit transaction speed compared to standalone chains.
2. Liquidity Fragmentation: ZK rollups can fragment liquidity within the ecosystem, making it harder for assets to move between applications in contrast to single-layer environments.
3. Composability Challenges: Permissionless composability is limited, as applications on different rollups cannot interact as freely as those on the same base layer.
4. Upgradability Risks: As a newer technology, rollups may face potential risks in maintaining and upgrading systems opposed to more established L1 blockchains.

Are ZK Rollups Possible on Bitcoin?

Yes, ZK rollups are theoretically possible on Bitcoin, but they face significant technical and structural challenges. Bitcoin's scripting language is limited compared to Ethereum, making it difficult to implement the complex computations required for zero-knowledge proofs directly.

However, with modifications or by using sidechains, ZK rollups could potentially be adapted to Bitcoin with Citrea being the most popular protocol that is building a such product right now.

Bottom Line

The top 5 ZK rollup projects of 2024 are Linea, ZKsync Era, Starknet, Polygon zkEVM, and Scroll, each bringing distinct strengths to the table. Linea has high demand while still being tokenless, while ZKsync Era is popular for its diverse protocol support, especially with decentralized exchanges.

Starknet tops the race in privacy-focused STARK technology, Polygon zkEVM is admired for its expansive suite of ZK rollups and substantial market presence, and Scroll is prominent by its developer-centric ecosystem and considerable DeFi engagement.