Scroll zkRollup: Layered Solution for Faster Ethereum

Scroll zkRollup: Enhancing Ethereum with zk-Proofs and Security

Scroll kEVM: Revolutionizing Ethereum's Scalability

Scroll zkEVM is a groundbreaking Layer 2 scaling solution for Ethereum, designed to enhance scalability, reduce transaction costs, and ensure security. By utilizing zero-knowledge rollups (zk-rollups), Scroll offers a more efficient and decentralized infrastructure for decentralized applications (dApps). This innovative approach tackles Ethereum's long-standing challenges of high gas fees and network congestion, offering a transformative solution for developers and users alike.

Background: Addressing Ethereum's Scalability Issues

Since its launch in 2015, Ethereum has experienced significant network congestion, high transaction fees, and slower processing times. These challenges arise from Ethereum's commitment to security and decentralization. Scroll zkEVM provides a solution by processing transactions off-chain, while still ensuring they are validated securely.

Rollups: The Future of Layer 2 Scaling

Rollups are a key component of Ethereum's roadmap. They process transactions off-chain, then post data on-chain, significantly increasing throughput without compromising decentralization. Scroll zkEVM takes this further by validating transactions with zero-knowledge proofs, ensuring that all computations are done correctly.

Scroll zkEVM: A Scalable and Secure Future

Scroll zkRollup is an advanced Layer 2 solution utilizing zero-knowledge rollups (zk-rollups) to enhance Ethereum's scalability, security, and reduce transaction costs. It consists of three key layers:

• Settlement Layer: Ensures data availability, manages transactions between Ethereum and Scroll, and verifies validity proofs.

• Sequencing Layer: Executes transactions through an Execution Node and Rollup Node, batching data for Layer 1 submission.

• Proving Layer: Generates zkEVM validity proofs to ensure transaction correctness, maintaining Ethereum’s security.

Execution Environment

Scroll uses Ethereum's Virtual Machine (EVM) with slight modifications to enhance the ZK proving process. The Execution Node in Scroll processes transactions from both Layer 1 and Layer 2, ensuring that the network remains decentralized and secure while supporting additional rollup mechanisms. Scroll’s execution environment ensures that the Ethereum ecosystem remains compatible with the ever-evolving blockchain landscape.

Transaction Lifecycle in Scroll

In Scroll, the transaction lifecycle passes through three phases: Confirmed, Committed, and Finalized. Once a transaction is executed and included in an L2 block, it becomes Confirmed. It becomes Committed when the transaction data is posted to Layer 1, and finally, Finalized after the proof is verified on L1, making it a canonical part of the Scroll chain.

Sequencing Transaction: Fast and Reliable Processing

Scroll’s L2 sequencer efficiently handles transactions through three modules:

• Sync Service: Detects new L1 messages and adds them to the L1 transaction queue.

• Mempool: Collects transactions submitted directly to the L2 sequencer.

• Executor: Processes both L1 and L2 transactions to generate L2 blocks.

This process ensures rapid transaction execution while maintaining Ethereum's decentralization and security.

The zkEVM: Powering EVM Execution

Scroll’s zkEVM is built in collaboration with the Privacy and Scaling Explorations (PSE) team and utilizes the Halo2 proving system. This combination allows for zk proofs that validate Ethereum transactions while minimizing latency and enhancing scalability. The hardware-focused design uses GPU provers for faster proof generation, making Scroll zkEVM ideal for handling high transaction volumes.

EVM Execution: Understanding the Core

The Ethereum Virtual Machine (EVM) serves as the execution environment, where it acts as a state transition function. Given an initial world state (S) and a transaction (T), the EVM computes a new world state (S'). The EVM operates over both transient data stores (stack and memory) and persistent stores (contract bytecode and storage), processing transactions step-by-step through opcodes.

Proving an EVM Execution: Ensuring Validity

Scroll zkEVM breaks down the execution of a transaction into an ordered list of opcode executions, known as the execution trace. Each opcode is validated to ensure that the state transition, from S to S', adheres to Ethereum’s specifications. zk proofs attest to the validity of these transitions, ensuring accuracy in all computations.

Conclusion: A Scalable Ethereum Solution

Scroll zkEVM represents a leap forward in Ethereum scalability, offering a secure, efficient, and hardware-optimized solution. By integrating zk proofs and maintaining full compatibility with Ethereum, Scroll zkEVM promises to transform the way decentralized applications operate on the blockchain.