Rollup Overview
What is a Rollup?
A Rollup is a powerful Layer 2 scaling solution. Its core idea is to move the bulk of transaction computation and state storage off-chain (to Layer 2) while posting a small amount of data for each transaction back on-chain (to Layer 1). By doing this, a Rollup leverages the security and decentralization of its Layer 1 to secure the Layer 2 network.
Gate Layer is built on this model as an Optimistic Rollup, using GateChain as its Layer 1.
How Gate Layer's Rollup Works
Gate Layer's workflow can be broken down into several key steps that together ensure high performance and security consistent with GateChain:
1. Off-Chain Execution
- Fast Processing: User-submitted transactions are first received by Gate Layer's Sequencer. The Sequencer is responsible for ordering and processing transactions, and immediately bundling them into L2 blocks.
- High Performance: Because this process occurs off-chain, it avoids the slower consensus process of the L1, allowing Gate Layer to achieve extremely high TPS (Transactions Per Second) and millisecond-level transaction confirmations.
2. Data Publication to GateChain
- Data Availability: To ensure the state of L2 can be verified by anyone, the transaction data must be publicly available. The
op-batchercomponent compresses the transaction data from multiple L2 blocks and then posts it to the L1 using EIP-4844blobs, which are supported by GateChain. - Low Cost: Using
blobsinstead of traditionalcalldatafor data posting significantly reduces L1 storage costs, which is a key reason for Gate Layer's low transaction fees.
3. State Commitment
- State Root: After L2 transactions are executed, a new L2 state is generated. The
op-proposercomponent calculates a unique cryptographic fingerprint of this new state, known as the State Root.
- Submission to L1: The
op-proposerperiodically submits this new state root to theDisputeGameFactorysmart contract deployed on GateChain (L1). This state root acts like a "snapshot summary" of the L2 at a specific point in time.
4. Optimistic Verification
- The "Optimistic" Assumption: As an Optimistic Rollup, Gate Layer "optimistically" assumes that all state roots submitted to the L1 are correct without needing immediate verification.
- Fault Challenge Period: Each state root, upon submission, enters a Fault Challenge Period. During this window, anyone (a Verifier) can check the transaction data on L1 and re-calculate the state root.
- Fraud Proofs: If a verifier finds that the state root on L1 does not match their own calculation, they can submit a Fraud Proof to issue a challenge. If the challenge is successful, the incorrect state root is removed, and its proposer is penalized. If no one challenges the state root within the challenge period, it is considered final.
Summary
Through this mechanism, Gate Layer cleverly offloads computation-intensive work to L2 while leveraging L1 GateChain as the data publication layer and the ultimate arbiter of truth. This achieves a massive leap in blockchain performance without sacrificing security.