How does zk-Rollup work? A comprehensive analysis of Taiko's Rollup-based Ethereum scaling architecture and verification mechanism.

The Ethereum mainnet’s transaction throughput bottleneck and gas fee volatility have always been core obstacles hindering its large-scale adoption. Layer 2 scaling solutions have therefore become a key track in the evolution of blockchain infrastructure. Among the many technical routes, ZK-Rollup (zero-knowledge rollup) is widely regarded as one of the ultimate Ethereum scaling solutions, thanks to the instant finality and high security provided by cryptographic proofs.

As the first Type 1 ZK-EVM project in the Ethereum ecosystem based on the Based Rollup architecture, Taiko quickly attracted a total value locked (TVL) of more than $200 million after its mainnet launch. Its core design philosophy is: don’t introduce a centralized sequencer—instead, return transaction ordering authority to Ethereum L1 validators, thereby inheriting Ethereum mainnet decentralization and anti-censorship characteristics.

Starting from the basic principles of zk-Rollup, this system breaks down Taiko’s scaling architecture—from the validity proof (Validity Proof) generation process, the transaction packaging and batching mechanism, the decentralized verification structure, and the interaction approach with the Ethereum mainnet—presenting readers with a technical path from technical principles to engineering implementation.

The Technical Principles of zk-Rollup and the Core Mechanisms of Validity Proof

From Off-Chain Computation to On-Chain Verification: zk-Rollup’s Basic Operating Logic

ZK-Rollup is a Layer 2 scaling solution. Its core idea is to move the computation and state storage for large volumes of transactions to off-chain execution, only submitting the most compact summary data and cryptographic proofs to the Ethereum mainnet. Specifically, ZK-Rollup packages thousands of transactions (“rolls up”) into a batch. After executing them off-chain, it generates a compact Validity Proof and submits it to a Rollup smart contract deployed on Ethereum for verification.

The core advantage of this mechanism is that the Ethereum mainnet does not need to verify each individual transaction; it only needs to verify a single cryptographic proof to confirm the correctness of the entire batch. Unlike traditional Optimistic Rollup, which relies on a 7-day challenge period, ZK-Rollup achieves instant finality through mathematical proofs. In 2026, the verification time for ZK solutions has been compressed to within 50 milliseconds, and the cost per transaction has dropped to below $0.01.

The Validity Proof Generation Process

Validity Proof is the foundation of ZK-Rollup security. Its generation process typically includes the following steps:

Step 1: Transaction execution and state update. After users initiate transactions on the Layer 2 network, the Rollup node executes these transactions off-chain and calculates the change to the state root. The state root is an account-state hash organized in a Merkle tree, representing the Rollup chain’s current state.

Step 2: Proof generation (proving). The Prover obtains the transaction batch and its execution trace, and uses a zero-knowledge proof system (such as zk-SNARK or zk-STARK) to generate a Validity Proof. The proof cryptographically asserts that, given the initial state root, after executing the batch of transactions, it can be correctly transformed into a new state root. During the proving process, no specific transaction details are leaked—only the conclusion that “the state transition is correct” is output.

Step 3: Proof submission and on-chain verification. The Prover submits the Validity Proof together with the new state root to the Rollup contract on the Ethereum mainnet. The on-chain verifier contract verifies the proof’s validity through mathematical operations; this process does not require re-executing transactions, and the computational cost is far lower than verifying each transaction one by one.

Step 4: Final state confirmation. Once the proof passes verification, the Rollup contract updates its recorded state root, and the batch of transactions attains finality at the Ethereum layer. Users can withdraw from the Rollup to the Ethereum mainnet without waiting for a challenge period.

At the proof generation layer, Taiko uses a Multi-Proof architecture that combines two independent systems: SGX (proof based on a trusted execution environment) and ZK proofs. Any single proof type is not considered sufficient—multiple independent proof systems must agree on the state transition in order to complete final verification. This design significantly improves the system’s security redundancy.

Transaction Packaging and Batching Mechanism: How to Achieve Efficient Off-Chain Aggregation

The economic logic of batching

Batching is the core means by which ZK-Rollup achieves scaling. Each execution in the off-chain virtual machine consumes computational resources, while submitting data to the Ethereum mainnet requires paying gas fees. The essence of batching is to find an optimal balance between “off-chain computation costs” and “on-chain data publication costs.”

ZK-Rollup compresses multiple transactions into a single batch. After generating a Validity Proof, it submits it to the mainnet in one go. Compared with submitting transactions individually, batching significantly reduces the average cost per transaction. According to Ethereum’s official documentation, ZK-Rollup reduces data size by using account indices instead of addresses, allowing each transaction to save about 28 bytes of on-chain data.

Taiko’s block proposal and batching process

In Taiko’s protocol design, the block proposer (Proposer) is responsible for packaging one or more L2 transactions into a block and submitting it to Ethereum L1 by calling the propose method of the Inbox contract. The proposal data is carried via blob-backed derivation sources.

Taiko completed the Shasta upgrade on mainnet in April 2026, bringing a major restructuring to the batching mechanism. In the upgraded protocol, the core contracts are streamlined into three modules: Inbox, Anchor, and SignalService. The block proposal cost dropped from about 1 million gas to about 45,000 gas—an approximately 22x reduction. The proving cost dropped from about 500,000 gas to about 280,000 gas—an approximately 8x reduction.

Decentralized Verification Structure: Taiko’s Based Rollup and Multi-Proof Architecture

Based Rollup: returning ordering power to Ethereum

Traditional Rollup solutions (such as Arbitrum and Optimism) rely on centralized sequencers run by the project team to package and order transactions. While this architecture improves efficiency, it introduces centralization risks: the sequencer can censor transactions, extract MEV, and even become a single point of failure.

Taiko’s Based Rollup architecture fundamentally changes this model. In a Based Rollup, transaction ordering is not handled by a sequencer controlled by the project, but is instead completed directly by Ethereum L1 validators. The ordering of L2 blocks is determined by Ethereum validators when they propose L1 blocks. This means:

• Maximum decentralization: no additional trust assumptions are introduced
• Complete anti-censorship: inherits the guarantees of Ethereum L1
• Permissionless participation: anyone can become a block proposer or prover

Taiko thus became the first Based Rollup-based L2 project on Ethereum. As stated in its official documentation: “No centralized sequencer. No compromise.”

Multi-Proof Verification System

Taiko’s verification architecture is completed collaboratively by multiple roles:

Proposer: Submits proposals containing one or more L2 blocks to Ethereum L1 via the Inbox contract.

Prover: Generates a Validity Proof (SGX + ZK) to confirm that the proposed blocks have been executed correctly.

Verifier contract: Orchestrates multiple sub-verifiers (SGX, ZK) on L1 for multi-proof verification.

In the post-Shasta-upgrade protocol, a successful proof submission directly completes finalization for the proven range. The Inbox contract checks whether the range is linked to the currently finalized head, writes checkpoints to SignalService, and updates the finalized proposal ID and block hash. There is no longer a separate “post-proof finalization” step—once a proposal range is proven, it is final.

Type 1 ZK-EVM: full Ethereum equivalence

Taiko runs an unmodified Ethereum execution layer (Type 1 ZK-EVM). Every opcode, every precompile, and every tool available on Ethereum can run directly on Taiko without any modifications. Developers deploy the same Solidity contracts using the same toolchain (Hardhat, Foundry, etc.).

This full bytecode-level equivalence makes Taiko one of the most compatible ZK-Rollups in the Ethereum ecosystem. In May 2026, Polygon zkEVM had just completed its Type 1 equivalence upgrade, while Taiko’s mainnet has run from its own launch with the positioning of a Type 1 ZK-EVM.

How Taiko Interacts with the Ethereum Mainnet

Cross-layer communication architecture

Taiko interacts with the Ethereum mainnet through a complete cross-chain communication system. The core components include:

Inbox: An L1 smart contract that manages proposal reception, proof submission, checkpoint recording, and finalization.

Anchor: An L2 smart contract that anchors L1 checkpoints and related metadata to the L2 chain.

Bridge: An asset- and message-cross-chain transmission system between L1 and L2.

SignalService: A low-level cross-chain signaling smart contract that provides Merkle proof-based message verification for the bridge.

Deposit and withdrawal process

When users deposit assets into Taiko, on the Ethereum mainnet they send the assets to the Rollup contract, and the contract records the deposit event. Once Taiko’s off-chain nodes detect this event, they mint the corresponding assets for the user on L2.

The withdrawal process relies on Validity Proof verification. Once the proof is accepted by the L1 verifier contract, users can extract assets from the Rollup contract without going through the 7-day challenge period required by Optimistic Rollup.

Recent security incidents and recovery

In June 2026, Taiko’s cross-chain bridge experienced a security incident involving approximately $1.7 million. The cause was that an SGX signing key in the Raiko multi-prover stack was publicly exposed on GitHub. The attacker used the leaked key to forge SGX prover authentication.

The Taiko team’s response demonstrated the effectiveness of its governance mechanism: the security committee quickly executed an on-chain fix, confirmed that no user funds were harmed, and the bridge assets were fully topped up in a 1:1 ratio. As of July 2, 2026, the bridge service had been restored and the network was running normally. Affected by this incident, the TAIKO token rebounded by about 75% within 24 hours, returning to $0.20.

Market performance and ecosystem progress

As of July 3, 2026 (Beijing time), according to Gate market data, Taiko (TAIKO) was priced at $0.13466. Its 24-hour trading volume was approximately $11.5928 million, its market capitalization was approximately $26.8818 million, and market sentiment was neutral. The total token supply is 1.00 billion, with a current circulating supply of approximately 198 million. The price increased 111.36% over the past 7 days and 39.27% over the past 30 days, but fell 64.07% over the past year.

In terms of ecosystem development, in early February 2026 Taiko deployed the ERC-8004 Agent Identity Registry, becoming one of the first L2s to support this standard. In the first month after mainnet launch, more than 45,000 AI agents had completed registration on the ERC-8004 network. Taiko’s TVL reached a peak of $81 million in June, with a monthly growth rate of 1,000%.

Conclusion

From the generation of Validity Proofs to transaction batching, from the decentralized ordering of Based Rollup to the multi-proof verification architecture, Taiko offers a Layer 2 scaling blueprint that balances technical completeness with alignment to Ethereum. Its Type 1 ZK-EVM ensures zero-cost migration for developers. The Based Rollup design inherits the decentralization guarantees of the Ethereum mainnet. The multi-proof architecture enhances system security through redundant verification.

By 2026, the Layer 2 ecosystem has moved from early-stage technical exploration into a mature phase of “modular upgrades + differentiated competition.” With instant finality and cryptographic security guarantees, ZK-Rollup is becoming a mainstream technical route for Ethereum scaling. The cost optimizations and architecture simplification achieved by Taiko after the Shasta upgrade, along with its expansion into emerging tracks such as AI agents, all indicate that this Based Rollup scaling solution is transitioning from theory to large-scale real-world application.

For readers who care about Ethereum scaling technology and the evolution of the Layer 2 ecosystem, understanding zk-Rollup’s operating mechanism and Taiko’s architectural choices is an important entry point to grasp the development trends of blockchain infrastructure.

FAQ

Q1: What are the core differences between zk-Rollup and Optimistic Rollup?

zk-Rollup uses Validity Proofs (validity proofs) to cryptographically ensure the correctness of each transaction, achieving instant finality; Optimistic Rollup assumes transactions are valid by default and relies on fraud proofs within a 7-day challenge period to discover errors. With zk-Rollup, withdrawals do not require waiting, while with Optimistic Rollup, they must go through the challenge window.

Q2: What does Taiko’s “Based Rollup” mean?

Based Rollup refers to a Rollup architecture that returns the right to order L2 transactions to Ethereum L1 validators. Unlike traditional Rollups that depend on centralized sequencers, Based Rollup inherits Ethereum mainnet’s anti-censorship and decentralization guarantees. Taiko is the first L2 project on Ethereum to adopt this architecture.

Q3: How does Taiko’s multi-proof system work?

Taiko uses two independent proof systems: SGX (trusted execution environment-based) and ZK. No single proof type is treated as a final conclusion—multiple independent proof systems must agree on the state transition for verification to be completed. This design significantly enhances system security through redundant verification.

Q4: What changes did Taiko’s Shasta upgrade bring?

The Shasta upgrade was deployed on mainnet in April 2026, streamlining the protocol’s core smart contracts into three modules: Inbox, Anchor, and SignalService. Block proposal costs dropped from about 1 million gas to about 45,000 gas (a 22x reduction), and proving costs dropped from about 500,000 gas to about 280,000 gas (an 8x reduction).

Q5: How does Taiko interact with the Ethereum mainnet?

Taiko interacts with the Ethereum mainnet through four core components: Inbox (L1 contract managing proposals and proof submission), Anchor (L2 contract anchoring L1 checkpoints), Bridge (cross-chain asset and message transfer), and SignalService (cross-chain signal verification). Deposits are recorded via L1 contracts, and withdrawals are executed directly after Validity Proof verification succeeds.