ZKsync Era vs Polygon zkEVM: An In-Depth Look

The layer 2 ecosystem of Ethereum is vibrant and competitive. There are leaders in the space, like Optimism and Arbitrum, which are now facing challenges from a couple of new entries in the space — ZKsync Era and Polygon zkEVM. These two layers 2 networks are powered by zero-knowledge proofs, which begs the question if they are any different, and if yes, what sets them apart from one another?

In this ZKsync Era vs Polygon zkEVM comparative analysis, we will answer all such questions.

ZKsync Era Overview

ZKsync Era is a layer 2 rollup on Ethereum. It is a trustless blockchain protocol that uses zero-knowledge validity proofs to offer low-cost transactions on Ethereum.

A rollup is a scalability solution where transactions are executed and stored off the Ethereum chain. The transaction data is bundled into a compressed package and sent to Ethereum with validity proofs to prove their legitimacy. Layer 2 chains inherit most of the security guarantees from Ethereum, albeit at a lower cost than layer 1 transactions.

Key Features:

• It offers Ethereum-like security. It inherits Ethereum's security with zk-proofs without using third-party validators.
• It supports permissionless EVM-compatible smart contracts.
• ZKsync offers fast proof proof generation while also maintaining Ethereum compatibility.
• It includes native account abstraction and paymaster features.
• It offers enhanced multi-layered scalability with a network of interconnected ZK Chains.

Polygon zkEVM Overview

Polygon zkEVM is a redesign of the original Polygon PoS chain. While the PoS chain operated as a Proof-of-Stake sidechain to Ethereum, zkEVM is a zero-knowledge layer 2 scaling solution that provides fast finality to off-chain transactions.

The original PoS network had three essential layers: 

• The Ethereum Layer – A set of smart contracts on Ethereum for validator record keeping.
• Heimdall Layer – A set of Proof of Stake nodes running parallel to Ethereum that commit Polygon Network checkpoints to the mainnet.
• Bor Layer – A set of block-producing nodes shuffled by Heimdall nodes.

The network also supported a two-way bridge between the PoS chain and Ethereum, allowing users to move assets like POL (previously MATIC) and ETH between the networks. 

Polygon PoS is now zkEVM Validium

A Validium has a higher throughput and lower cost than standard ZK-Rollups. Validium trades off data availability guarantees offered by layer 1 to achieve a higher throughput and lower transaction cost. A Validium model works like a standard ZK-Rollup but skips sharing transaction data with Ethereum.

The Ethereum validators still have access to zk-proofs and state commitments, enabling them to prove if all transactions were correctly included in the rollup state. However, they cannot verify the validity of the rollup state, a situation known as lack of data availability. 

The original PoS network will now operate using smart contracts on Ethereum and will serve as the data availability layer for zkEVM. Its validators will still continue consensus processes but with smart contracts on Ethereum rather than a dedicated sidechain.

Ethereum Equivalence

Vitalik Buterin categorized zkEVMs into four types based on their level of EVM equivalence:

• Type 1: Fully EVM-equivalent, aiming for perfect compatibility with Ethereum.
• Type 2: Close to EVM-equivalent but requires minor modifications to existing Ethereum applications.
• Type 3: EVM-compatible but uses custom modifications that deviate from the standard EVM.
• Type 4: EVM-like but requires substantial changes to existing code. 

Polygon zkEVM is classified as Type 2. It achieves high EVM equivalence by ensuring that most Ethereum smart contracts, tools, and wallets work seamlessly with minimal modifications. This design choice balances performance and compatibility, allowing developers to leverage existing Ethereum infrastructure with minor adjustments.

ZKsync Era is a Type 4 ZK-EVM, meaning that the proof generation times are extremely fast, transaction speed is high, and centralization risks are reduced. The ZKsync team has improved EVM compatibility by introducing custom compilers, zksolc and zkvyper, that let developers write smart contracts in Solidity or Vyper.

Developers can also use existing tools and libraries from Ethereum, addressing several compatibility drawbacks of type-4 ZK-EVMs. This approach offers flexibility and performance improvements but may require more significant code changes compared to Polygon zkEVM.

Both platforms provide unique advantages in terms of scalability, cost-efficiency, and developer experience, catering to different needs within the Ethereum ecosystem.

Data Availability

Polygon zkEVM and ZKsync Era leverage Ethereum as their primary data availability layer. This approach ensures that transaction data and validity proofs are securely stored and accessible on the Ethereum blockchain, inheriting its robust security and decentralization.

Polygon zkEVM: Polygon Avail

Polygon Avail is Polygon's dedicated data availability solution. It has been developed to handle off-chain data availability, ensuring that all necessary data for verifying zk-rollups is accessible even when stored off-chain. Polygon Avail provides several key features:

• Decentralized Data Availability: Ensures data is distributed across a network of nodes, reducing the risk of data unavailability or tampering.
• Scalability: By offloading data availability from the main Ethereum chain, Polygon Avail significantly enhances the scalability of the zkEVM.
• Flexibility: It can be integrated with various blockchain solutions beyond Polygon zkEVM, offering a versatile data availability solution for multiple Layer 2 and Layer 3 protocols.

Recently, Polygon Avail was spun out of Polygon Labs as a standalone company led by Polygon co-founder Anurag Arjun. This strategic move aims to accelerate its development and adoption across the blockchain ecosystem​.

ZKsync Era: zkPorter

zkPorter is Matter Labs' innovative data availability product, designed to complement ZKsync Era. Announced in 2021, zkPorter introduces a hybrid approach to data availability by offering users the choice between:

• zk-Rollup Accounts: Store data on-chain, providing the highest level of security by leveraging Ethereum's security model.
• zk-Porter Accounts: Store data off-chain, significantly reducing costs and increasing transaction throughput. A network of validators manages this off-chain data, ensuring decentralization and security.

Key features of zkPorter include:

• Enhanced Scalability: By moving data off-chain, zkPorter can handle a much higher volume of transactions, facilitating greater scalability for ZKsync Era.
• Cost Efficiency: Off-chain data storage drastically reduces the costs associated with data availability, making it a more economical choice for users and developers.
• Security: zkPorter employs robust cryptographic techniques to ensure the integrity and availability of off-chain data, maintaining a high level of trust and reliability.

zkPorter is planned to be integrated into ZKsync Era as an option for decentralized data availability later in their roadmap, enhancing the flexibility and scalability of the ZKsync ecosystem​.

Comparative Analysis

Data Availability Approaches:

• Polygon zkEVM with Polygon Avail: Focuses on providing an option between two data availability solutions. Offloading data availability to a third party enhances scalability and reduces costs while maintaining security through decentralized storage.
• ZKsync Era with zkPorter: Offers a hybrid approach, allowing users to choose between on-chain and off-chain data storage. This flexibility caters to different security and cost preferences, making it a versatile solution for varied user needs.

Scalability and Cost:

• Polygon Avail: Enhances scalability by providing off-chain data availability, reducing the Ethereum mainnet load, and lowering transaction costs.
• zkPorter: Increases scalability and cost efficiency by offering off-chain data storage, which is managed by a decentralized network of validators.

Security: 

• Both solutions employ advanced cryptographic techniques to ensure the integrity and availability of data, maintaining a high level of security while providing scalability and cost benefits.

Future Integration and Development:

• Polygon Avail: It has already spun out as a standalone company, indicating a strong commitment to its development and integration across the blockchain ecosystem.
• zkPorter: Scheduled for future integration into ZKsync Era, promising a flexible and scalable data availability solution that complements ZKsync's existing architecture.

In conclusion, both Polygon zkEVM and ZKsync Era are developing robust data availability solutions that enhance scalability, reduce costs, and maintain security. Polygon Avail offers a versatile, standalone approach, while zkPorter provides a hybrid model that caters to diverse user needs.

On-chain Metrics

Here are comprehensive on-chain metrics for Polygon zkEVM and ZKsync Era.

Total Value Locked (TVL):

Polygon zkEVM: The TVL for Polygon zkEVM stands at around $120 million, with a peak of $190 million in March 2024.

ZKsync Era: The TVL for ZKsync Era is significantly higher at $1.11 billion, with a peak of $1.6 billion in June 2024.

Activity:

Polygon zkEVM: This network sees an average transaction rate of 12-14 transactions per second (TPS), predominantly Ethereum transactions with minimal Layer 2 application activity.

ZKsync Era: ZKsync Era also averages around 12 TPS, but these transactions are a balanced mix of Ethereum and Layer 2 application transactions.

Average Transaction Fee:

Both networks have benefited from lower transaction fees post-Ethereum's proto-danksharding upgrade. However, ZKsync Era's fees are significantly lower, primarily due to its use of a more scalable zk-proof design that prioritizes speed and efficiency over full EVM equivalence.

Critical Analysis

Why is There an Astronomical Difference in Their TVL?

• ZKsync Era's Higher TVL: The substantial difference in TVL between ZKsync Era and Polygon zkEVM can be attributed to several factors:
  • DApp Ecosystem: ZKsync Era has attracted a more extensive range of DeFi applications, contributing to higher TVL, including popular protocols and integrations that draw significant capital into the ecosystem​.
  • User Incentives and Airdrop Speculation: ZKsync Era has seen a surge in activity due to speculation around potential airdrops. This speculation incentivizes users to lock more funds into the network in hopes of qualifying for future rewards​.
  • Venture Capital Funding: ZKsync Era's development has been bolstered by substantial funding from venture capital, which has been used to foster ecosystem growth and attract more projects​.

Why is DApp Activity in Polygon zkEVM Almost Absent?

• Focus on Ethereum Transactions: Polygon zkEVM focuses primarily on Ethereum transaction scalability rather than fostering a diverse ecosystem of Layer 2 applications. This approach limits the number of innovative DApps specifically designed for Layer 2​.
• Strategic Differences: Polygon zkEVM is designed to be EVM equivalent, which ensures compatibility with Ethereum but at higher transaction fees than ZKsync Era. This optimization makes it less attractive for certain high-frequency or low-margin applications that thrive in a lower fee environment​​.

How Do the Different Proof Designs Impact Fees?

• ZKsync Era: By being EVM compatible rather than equivalent, ZKsync Era uses a more efficient zk-proof design to process transactions faster and at a lower cost. This design sacrifices some level of compatibility for enhanced scalability and lower operational costs​​.
• Polygon zkEVM: The choice to maintain EVM equivalence means that Polygon zkEVM inherently incurs higher fees due to its proof system's increased complexity and computational requirements. This design decision aligns with its goal of providing seamless integration with existing Ethereum infrastructure but results in higher costs​.

What Types of DApps and Users Are Attracting High TVL on ZKsync Era?

• DeFi Protocols: ZKsync Era has become a hub for DeFi applications, attracting protocols focused on lending, borrowing, and decentralized exchanges. The low fees and high transaction throughput make it an ideal platform for these types of applications​​.
• Active Speculators: The anticipation of airdrops has driven significant user engagement and capital influx. Users are actively participating in the network to maximize their chances of receiving future governance tokens​​.

Conclusion

The comparison between Polygon zkEVM and ZKsync Era highlights the different strategic approaches and their impacts on on-chain metrics. ZKsync Era's focus on efficient zk-proof designs, coupled with a robust DeFi ecosystem and user incentives, has resulted in higher TVL and broader application activity. 

In contrast, Polygon zkEVM's emphasis on maintaining EVM equivalence and Ethereum transaction scalability has limited its attractiveness to high-frequency applications but ensures strong compatibility with Ethereum. As Layer 3 solutions continue to evolve, these dynamics will shape the future of decentralized applications and their deployment across various blockchain networks.

Tokenomics and Utility

Here is a summary of tokenomics and utilities of the these layer 2 tokens:

ZKsync Era's ZK Token

• Total Supply: 21 billion ZK tokens.
• Initial Distribution:
  • Token Assembly: 29.27% (allocated by the Token Assembly).
  • Ecosystem Initiatives: 19.90% (administered by the ZKsync Foundation for grants, incentives, and other initiatives).
  • Airdrop: 17.50% (distributed through a one-time airdrop).
  • Investors: 17.19%.
  • Team: 16.14% (allocated to Matter Labs employees).
  • Lock-Up Periods: Investor and team tokens are locked up for four years (June 2024 to June 2028), with a one-year cliff and subsequent monthly unlocks.
• Utility:
  • Governance: ZK token holders can participate in the governance of the ZKsync ecosystem.
  • Transaction Fees: These are used to pay transaction fees on the ZKsync Era network.
  • Staking and Incentives: Tokens are used in staking mechanisms to secure the network and incentivize user participation in various ecosystem activities.

Polygon's POL Token

• Total Supply: POL is the successor to MATIC, with a planned migration process. The total supply of POL and its specific distribution details are still being finalized as of the latest updates.
• Initial Distribution (MATIC):
  • Ecosystem: A significant portion is allocated to ecosystem development.
  • Staking: Used for staking rewards to secure the network.
  • Team and Advisors: Allocated to the founding team and early advisors.
  • Investors: Distributed to early investors and through various funding rounds.
• Utility:
  • Governance: POL token holders can participate in the governance of the Polygon ecosystem.
  • Transaction Fees: POL is used to pay for transaction fees on the Polygon network.
  • Staking: Tokens are staked by validators to secure the network, and stakers earn rewards.
  • Ecosystem Development: POL is used to fund ecosystem initiatives and incentivize developer activity.

Comparative Analysis

• Supply and Distribution:
  • ZKsync Era has a clearly defined total supply and a structured distribution plan, with a significant focus on ecosystem initiatives and community airdrops.
  • Polygon is transitioning from MATIC to POL, with a focus on staking and ecosystem development, though exact distribution details for POL are still emerging.
• Utility: Both tokens serve governance, transaction fee payments, and staking purposes. However, ZKsync's capped minter system and Polygon's integration with Polygon Avail offer unique mechanisms for managing token supply and data availability.
• Lock-Up and Vesting: ZKsync Era has a detailed lock-up schedule for team and investor tokens, ensuring gradual release and reducing market impact. Polygon's lock-up details for POL are aligned with typical vesting schedules but are yet to be fully detailed.
• Ecosystem Focus:
  • ZKsync strongly emphasizes community involvement and ecosystem incentives through its distribution model.
  • Polygon focuses on scalability and data availability solutions, with POL playing a crucial role in these strategic areas.

In summary, both ZKsync Era's ZK token and Polygon's POL token are designed to support their respective ecosystems with robust governance, transaction, and staking functionalities. Their unique features, such as ZKsync's capped minters and Polygon's Avail integration, highlight their strategic approaches to scalability and ecosystem growth. 

ZKsync Era vs Polygon zkEVM: Final Thoughts

Choosing between Polygon zkEVM and ZKsync Era depends on your specific needs and priorities. Both networks offer unique strengths and cater to blockchain scalability and utility aspects.

Key Points of Comparison:

• Architecture Design: Polygon zkEVM, with its integration of Polygon Avail, focuses on providing robust off-chain data availability and seamless EVM equivalence. ZKsync Era, leveraging zkPorter, offers a hybrid approach to data availability, allowing users to choose between on-chain and off-chain storage for enhanced flexibility and cost efficiency.
• EVM Equivalence: Polygon zkEVM is classified as Type 2, ensuring most Ethereum applications work seamlessly with minimal changes. ZKsync Era, closer to Type 3, offers EVM compatibility with more extensive code adjustments but provides greater flexibility in language support.
• Tokenomics and Utility: The ZK token of ZKsync Era and the POL token of Polygon both serve governance, transaction fees, and staking purposes. ZKsync's unique capped minter system and Polygon's integration with Avail highlight their respective approaches to managing token supply and enhancing network functionality.

Practical Recommendations:

• For Developers: If you seek minimal friction in migrating Ethereum applications, Polygon zkEVM's Type 2 EVM equivalence is advantageous. It allows developers to port existing Ethereum dApps with little to no modification, providing a familiar environment with improved scalability.
• For Cost Efficiency: ZKsync Era's zkPorter offers a cost-effective solution by allowing off-chain data storage, significantly reducing transaction costs. This makes it a compelling choice for applications with high transaction volumes where cost savings are crucial.
• For Data Availability and Security: Both networks provide robust data availability solutions, but Polygon Avail's standalone model might appeal more to those looking for a dedicated data availability service. ZKsync's hybrid model with zkPorter is ideal for users needing flexible security and cost balance.
• For Ecosystem Participation: ZKsync's strong community focus through its extensive airdrop and ecosystem incentives can be appealing if you are looking to be actively involved in governance and community-driven initiatives.

In conclusion, the choice between Polygon zkEVM and ZKsync Era should be guided by your specific use case, whether it's seamless EVM compatibility, cost efficiency, robust data availability, or active ecosystem participation. Both platforms are pushing the boundaries of blockchain scalability, and your selection should align with your project's goals and resource considerations.