zkSync is a Layer 2 (L2) blockchain that operates on top of Ethereum, using zero-knowledge proofs (ZK-proofs) to bundle, or 'roll up,' thousands of transactions off-chain. This process generates a cryptographic proof, called a validity proof or SNARK, which is then posted to the Ethereum mainnet (Layer 1). This architecture allows zkSync to inherit Ethereum's security while offering significantly higher transaction speeds and drastically lower gas fees for users, making decentralized applications (dApps) more practical and affordable.
LABS
Glossary
zkSync
zkSync is a zero-knowledge rollup (ZK-rollup) scaling solution for Ethereum that bundles transactions off-chain and submits validity proofs to the mainnet, enabling high throughput and low fees.
Chainscore © 2026
definition
LAYER 2 SCALING SOLUTION
What is zkSync?
zkSync is a zero-knowledge rollup (ZK-rollup) scaling solution for the Ethereum blockchain, designed to increase transaction throughput and reduce costs while maintaining the security of the Ethereum mainnet.
The core technology enabling zkSync is the zkEVM (zero-knowledge Ethereum Virtual Machine), a virtual machine compatible with the Ethereum EVM. This compatibility is crucial as it allows developers to deploy existing smart contracts written in Solidity or Vyper with minimal modifications. zkSync Era, the platform's major evolution, introduced this zkEVM, moving beyond simple payments to support a full suite of DeFi, NFT, and complex dApp functionalities, all secured by cryptographic proofs.
Key features that distinguish zkSync include its focus on user experience and sovereignty. It offers native account abstraction, allowing for features like gasless transactions and social recovery wallets. Furthermore, its ZK-rollup design ensures trustless security; users can always withdraw their assets to Ethereum L1 without relying on third-party validators, as the cryptographic proof guarantees the correctness of all L2 state transitions. This makes it a validium-like option when data availability is managed off-chain for even lower costs.
how-it-works
ARCHITECTURE OVERVIEW
How zkSync Works
zkSync is a Layer 2 scaling solution for Ethereum that utilizes zero-knowledge rollup technology to provide high-throughput, low-cost transactions while inheriting Ethereum's security.
zkSync operates as a zero-knowledge rollup (ZK-rollup), a Layer 2 architecture that executes transactions off-chain and then posts cryptographic proofs of their validity to the Ethereum mainnet. This process bundles, or 'rolls up,' hundreds of transactions into a single compressed batch. The core innovation is the zk-SNARK (Zero-Knowledge Succinct Non-Interactive Argument of Knowledge) proof, which allows the system to verify that all transactions in a batch are correct without revealing their underlying data, ensuring both privacy and efficiency.
The system's architecture consists of several key components working in concert. Users deposit assets into a smart contract on Ethereum Layer 1, which are then represented on the zkSync Layer 2 chain. A network of validators processes transactions off-chain, updating the state of the zkSync ledger. After processing a batch, a validator generates a validity proof (the zk-SNARK) and submits it, along with the new state root, to the Ethereum smart contract. The contract verifies the proof's cryptographic integrity in a single, low-cost computation, finalizing the state transition.
For users, interaction is seamless. They sign transactions using their Ethereum wallet, which are then relayed to zkSync sequencers. A critical feature is account abstraction, which allows smart contracts to pay gas fees on behalf of users and supports signature schemes beyond standard ECDSA. Once a batch is proven on Ethereum, funds can be withdrawn back to Layer 1 via a trustless process, as the validity proof guarantees the correctness of the user's balance within the rollup state.
zkSync Era, the latest major version, introduced a zkEVM (zero-knowledge Ethereum Virtual Machine). This is a virtual machine compatible with the Ethereum EVM opcodes, allowing developers to deploy existing Solidity and Vyper smart contracts with minimal modifications. The zkEVM executes contract logic off-chain and generates proofs of correct execution, enabling scalable decentralized applications (dApps) with low gas costs while maintaining composability within the zkSync ecosystem.
The security model is defined by cryptographic guarantees rather than economic incentives. The system's security is inherited from Ethereum because the integrity of the rollup state depends solely on the verification of the zero-knowledge proofs on Layer 1. As long as the underlying cryptography (e.g., the elliptic curve and proof system) is secure and the Ethereum base layer is live, the assets and state within zkSync are protected, making it a validium-like or zkRollup solution depending on its data availability configuration.
key-features
ZK-ROLLUP ARCHITECTURE
Key Features
zkSync is a ZK-rollup scaling solution for Ethereum, leveraging zero-knowledge proofs to enable high-throughput, low-cost transactions while inheriting Ethereum's security.
06
Fast Finality & Withdrawals
Transactions achieve fast finality on zkSync (often under 1 second) once included in a block. For moving assets back to Ethereum L1, the protocol uses a trustless bridge. Withdrawals are secured by ZK proofs and typically complete after a challenge period (currently ~24 hours for standard exits), which is shorter than optimistic rollup challenge windows.
ecosystem-usage
ZK-ROLLUP
Ecosystem and Usage
zkSync is a ZK-rollup scaling solution for Ethereum, utilizing zero-knowledge proofs to provide secure, low-cost transactions. Its ecosystem is built around core primitives like native account abstraction and a hyper-connected Layer 2 network.
COMPARISON MATRIX
zkSync vs. Other Scaling Solutions
A technical comparison of zkSync Era (ZK-Rollup) against other major Ethereum scaling approaches.
| Feature / Metric | zkSync Era (ZK-Rollup) | Optimistic Rollups (e.g., Optimism, Arbitrum) | Sidechains (e.g., Polygon PoS) | Validiums (e.g., Immutable X) |
|---|---|---|---|---|
Core Security Model | Inherits Ethereum security via validity proofs | Inherits Ethereum security via fraud proofs (challenge period) | Independent consensus (e.g., PoS) with bridge security | Data availability off-chain, security via validity proofs |
Time to Finality on L1 | ~1 hour | ~1 week (challenge period) | Instant (own chain finality) | ~1 hour |
Transaction Cost (Typical) | $0.10 - $0.50 | $0.20 - $1.00 | < $0.01 | < $0.10 |
EVM Compatibility | zkEVM (bytecode-compatible) | EVM-equivalent (OVM, Arbitrum Nitro) | EVM-compatible | Application-specific (often non-EVM) |
Data Availability | On-chain (calldata) | On-chain (calldata) | On-chain (checkpoints) / Off-chain | Off-chain (Data Availability Committee) |
Trust Assumptions | Trustless (cryptographic proofs only) | 1-of-N honest validator (for fraud proof) | Trust in sidechain validators & bridge | Trust in Data Availability Committee |
Withdrawal Time to L1 | ~1 hour | ~1 week | ~10 min - 3 hours (bridge delay) | ~1 hour |
Native Account Abstraction |
technical-details
TECHNICAL DETAILS
zkSync
zkSync is a Layer 2 scaling solution for Ethereum that leverages zero-knowledge rollup technology to provide high-throughput, low-cost transactions while maintaining the security of the Ethereum mainnet.
zkSync is a zero-knowledge rollup (ZK-rollup), a type of Layer 2 scaling protocol that bundles, or 'rolls up,' hundreds of transactions into a single cryptographic proof. This proof, known as a ZK-SNARK (Zero-Knowledge Succinct Non-Interactive Argument of Knowledge), is then submitted to the Ethereum mainnet for verification. The core innovation is that this proof validates the correctness of all transactions in the batch without revealing their underlying data, ensuring both privacy and massive scalability by reducing on-chain data and computation.
The architecture of zkSync consists of two primary components: the zkSync Virtual Machine (zkVM) and the zkEVM. The original zkVM executes transactions in a custom, ZK-friendly environment. Its evolution, zkSync Era, introduced a zkEVM (zero-knowledge Ethereum Virtual Machine) that is bytecode-compatible with Ethereum, meaning it can natively execute unmodified Ethereum smart contracts. This significantly improves developer experience by supporting Solidity and Vyper, while the zkSync prover generates the cryptographic proofs of correct execution off-chain.
From a user and developer perspective, interacting with zkSync involves depositing assets from Ethereum Layer 1 into a smart contract, after which all transactions occur on the high-speed Layer 2 chain. Finality is achieved when the validity proof is posted to Ethereum. Key technical features include native account abstraction, allowing smart contract logic to sponsor transaction fees, and hyperscalability through its proof system. Security is inherited from Ethereum, as the validity of the Layer 2 state is cryptographically guaranteed by the posted proofs, making fraud economically impossible.
security-considerations
ZK-ROLLUP
Security Model and Considerations
zkSync Era's security is derived from its underlying cryptographic proofs and the integrity of the Ethereum L1. This section details the core components that ensure the validity and safety of the rollup state.
ZK-ROLLUPS
Common Misconceptions
zkSync is a leading Layer 2 scaling solution, but its underlying technology and trade-offs are often misunderstood. This section clarifies frequent points of confusion about its architecture, security, and capabilities.
No, zkSync is not a standalone blockchain; it is a ZK-Rollup, a Layer 2 (L2) scaling solution built on top of Ethereum. It bundles, or "rolls up," thousands of transactions off-chain, generates a cryptographic proof of their validity (a ZK-SNARK or ZK-STARK), and posts only this compact proof to the Ethereum mainnet. This architecture allows zkSync to inherit Ethereum's security and decentralization while offering significantly higher throughput and lower fees. Users interact with zkSync's network, but the ultimate settlement and data availability remain secured by Ethereum Layer 1.
ZK SYNC
Frequently Asked Questions
Essential questions and answers about zkSync, a leading Layer 2 scaling solution for Ethereum using zero-knowledge proofs.
zkSync is a Layer 2 scaling solution for Ethereum that uses ZK-Rollup technology to bundle hundreds of transactions into a single, compressed batch. It works by executing transactions off-chain and then generating a cryptographic proof, called a Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARK), which is posted to the Ethereum mainnet. This proof cryptographically validates the correctness of all transactions in the batch without revealing their details, enabling faster and cheaper transactions while inheriting Ethereum's security. The core components are the zkSync Era Virtual Machine (zkEVM) for smart contract execution and a decentralized sequencer network for transaction ordering.
ENQUIRY
Get In Touch
today.
Our experts will offer a free quote and a 30min call to discuss your project.
NDA Protected
Confidentiality24h Response
Time to ValueDirectly to Engineering Team
No Sales Fluff10+
Protocols Shipped
$20M+
TVL Overall