Scroll’s bytecode compatibility and September milestone

Scroll’s weekly proof submissions reached 1.2 million in September, surpassing zkSync Era.

This volume shows the adoption of its Type 2 zkEVM architecture. Unlike zkSync Era, which utilizes Type 4 compatibility for high-level languages like Solidity or Yul, Scroll provides bytecode-level equivalence. Type 4 systems work by taking smart contract source code and compiling it to a language designed to be ZK-SNARK-friendly. This can result in different contract addresses than the EVM, which breaks applications relying on counterfactual contracts or ERC-4337 wallets. This distinction means the network proves Ethereum bytecode itself rather than a compiled alternative. Applications behave exactly as they do on Ethereum L1. Deployment requires no extra work. This level of equivalence ensures the execution environment remains identical to Ethereum. Type 2 zkEVMs like Scroll and Polygon Hermez make changes to data structures such as the block structure and state tree. Because the EVM cannot access these structures directly, applications that work on Ethereum function on Scroll without modification.

Performance metrics and network shifts

Scroll faces competition. Ether.fi moved its Cash product and user activity to Optimism, causing Scroll transaction fees to jump 296% between April 6 and April 8. This migration caused Scroll’s TVL to drop 90%, falling from $232 million to $23.2 million. It remains expensive. While the Uniswap V3 router processed 1.8 million transactions on the Scroll testnet, the mainnet launch remains a focus for growth. The Uniswap DAO targets $100M in TVL within two months of the mainnet deployment. Fees jumped 296%. The network’s single sequencer reported inflated L1 gas prices to the L2 oracle contract around 09:00 UTC on March 31st. In most cases, transactions are included in the next block in decreasing order of their tips, but this ordering is not guaranteed by the protocol. Median USDC transfer costs $0.06 on Scroll, compared to $0.05 on zkSync Era and $0.04 on Linea. Median DEX swap costs $0.27 on Scroll, compared to $0.21 on zkSync Era and $0.18 on Linea. The median transaction fee on Scroll dropped from $0.62 to $0.15 after the network enabled blobs via the Bernoulli upgrade. This upgrade also added SHA2-256 to improve security and efficiency for dapps.

While the network aims for seamless integration, the high hardware requirements for bytecode-compatible proving may restrict the prover set to well-resourced entities, which undermines decentralization goals and creates censorship vectors.

Opcode behaviors and technical risks

The network’s design introduces specific opcode variations. Scroll disables the SELFDESTRUCT opcode entirely. It also returns 0 for the DIFFICULTY or PREVRANDAO opcodes. You should audit precompile gas schedules for cost deviations. Scroll targets full bytecode-level equivalence by supporting exact EVM opcodes and precompiles without recompilation. This choice minimizes developer lock-in because dApps can migrate between Scroll and other EVM chains with zero code changes. However, supporting exact EVM opcode behavior in ZK circuits increases circuit size and the audit surface. This increases the probability of a soundness bug that allows invalid state transitions.

The high hardware requirements for bytecode-compatible proving create censorship vectors.

The sequencer on Scroll prioritizes executable transactions based on their tip. During congestion periods, blocks are sealed as soon as they are full instead of waiting for the 3-second interval. During normal hours, blocks are sealed at 3-second intervals to ensure a consistent user experience. The Uniswap DAO aims to capture the market by integrating Scroll into its user interface. This follows a testnet period where the Uniswap V3 router processed 1.8 million transactions. Scroll’s bytecode compatibility provides the best path for developers who prioritize easy migration.

Will the network maintain its growth?