[Constitutional] ArbOS 31 “Bianca” (Stylus, RIP-7212 Support, Nova Fee Router)

Abstract

This AIP proposes the activation of ArbOS 31 on Arbitrum One and Arbitrum Nova. This ArbOS upgrade brings a number of improvements, including:

• Activating Arbitrum Stylus to enable developers to build the next generation of Rust or C++ applications on the EVM.
• New precompile for verifying the secp256r1 elliptical curve (as part of RIP-7212 1)
• Change to fee collection on Arbitrum Nova, making it easier for ArbitrumDAO to manage and access the funds.

This AIP combines the following three temperature checks:

• AIP: Activate Stylus and Enable Next-Gen WebAssembly Smart Contracts 1
• AIP: Support RIP-7212 for Account Abstraction Wallets 1
• AIP: Nova Fee Router Proposal 2

A new ArbOS 31 “Bianca” was released between the time of the temperature check votes and submitting this proposal. ArbOS 31 release builds upon ArbOS 30 and includes new optimizations that were discovered during rigorous testing and feedback from Stylus teams. The ArbOS upgrade is shipped as a new Nitro node release alongside new upgrades to the rollup contracts for Arbitrum One and Arbitrum Nova.

Note: ArbOS 31 “Bianca” will be the canonical ArbOS version for the “Bianca” family of releases.

Since the DAO has already signaled support for the adoption of all three changes in all three temperature checks, this proposal will proceed to an on-chain AIP on Tally next.

Changes included

1. Activation of Arbitrum Stylus: a new WebAssembly-based (WASM) VM to support smart contracts written in Rust and C++

Stylus is an upgrade to the node software that powers all Arbitrum chains. This upgrade introduces a new WASM-based Virtual Machine (VM) that runs alongside the EVM. This enables developers to write smart contracts in new programming languages, like Rust, that are more efficient than Solidity smart contracts.

Stylus is a first-of-its-kind technology resulting from breakthrough engineering efforts in the Arbitrum ecosystem. Unlike other alternative VMs, the Stylus VM is not a replacement for the EVM & is instead purely additive to the EVM. This means that Stylus contracts and EVM contracts are fully interoperable. The two VMs work together to facilitate state transitions, each playing their part in executing their respective bytecode. Support for more memory efficient and safer languages will unlock a new generation of applications that were previously impossible to build on the EVM.

The Stylus VM and fraud prover were originally developed as a fork of the Nitro codebase before. The Stylus codebase has since been audited (Trail of Bits audit report 1) and merged back into the Nitro codebase:

• GitHub - OffchainLabs/stylus: Stylus VM and Fraud Prover
  • Merged into the Nitro codebase in: Arbitrum Stylus by rachel-bousfield · Pull Request #2242 · OffchainLabs/nitro · GitHub and Stylus v2 by tsahee · Pull Request #2425 · OffchainLabs/nitro · GitHub
• GitHub - OffchainLabs/stylus-geth
  • Merged into Offchain Labs’ fork of Geth in: Arbitrum Stylus by rachel-bousfield · Pull Request #305 · OffchainLabs/go-ethereum · GitHub
• GitHub - OffchainLabs/stylus-contracts
  • Merged into the Nitro-contracts codebase in: Arbitrum Stylus by rachel-bousfield · Pull Request #170 · OffchainLabs/nitro-contracts · GitHub

Stylus contracts can be written using the Stylus SDK, which employs Solidity-equivalent ABIs and storage patterns to ensure cross-language interoperability. For example, existing Solidity DEXs can list Rust tokens without modification. New SDKs for additional programming languages can be added over time. Current SDK repositories:

• Rust SDK: GitHub - OffchainLabs/stylus-sdk-rs: Rust Smart Contracts on Arbitrum
• C/C++ SDK: GitHub - OffchainLabs/stylus-sdk-c: C/C++ Smart Contracts on Arbitrum
• Stylus CLI: GitHub - OffchainLabs/cargo-stylus: Cargo subcommand for developing Arbitrum Stylus projects in Rust

If you would like to better understand the lifecycle of a Stylus contract, head over to A Gentle Introduction: Stylus 1. For teams who are curious to learn more about how Stylus is expected to interact with their project’s existing infrastructure, we encourage folks to check out this Stylus launch ecosystem one-pager.

Note: Support for Stylus contract verification is currently under development by major block explorers. We expect that contract verification will be fully supported before ArbOS 31 Bianca gets activated on Arbitrum One and Arbitrum Nova, pending the DAO’s decision to adopt this proposal.

2. Addition of a new pre-compile, to Arbitrum Nitro, that reduces the costs of verifying the secp256r1 elliptic curve as part of RIP-7212 1

Passkeys offer a solution that removes the need for a web3 user to personally store a private key for their wallet. Passkeys accomplish this by leveraging WebAuthn, a global standard for passwordless authentication used by Google, Facebook, Microsoft, and all major web browsers. The private key generated when creating a passkey can be encrypted and can only be decrypted using a specialized hardware module called the Secure Enclave. The Secure Enclave ensures a user’s private key can never leave the device, transforming any compatible device into a hardware wallet. Users can authorize transactions with biometric features like Touch ID or Face ID when using passkey-based wallets for key management. These qualities add flexibility and significantly improve UX while maintaining high security.

Adding support for RIP-7212 1 decreases the costs of verifying the secp256r1 curve on-chain by 99% when compared to current implementations, making them more feasible for everyday use and enabling dApp developers and protocols to offer their users improved UX on Arbitrum One and Arbitrum Nova. Without a precompile, verifying this signature on-chain is extremely expensive. Passkey-based wallets offer a better level of security than a typical EOA and seamless cross-device support. Many wallets, and notably, apps using embedded wallets, have been requesting this feature for over a year.

The specifications of RIP-7212 1, including test cases, can be found in the RIP repository 1. If approved, Arbitrum One and Arbitrum Nova will use this specification as the reference for implementation. The Ethereum Magicians Forum discusses design decisions, iterations, and the transformation of the proposal from an EIP (Ethereum Improvement Proposal) to a RIP.

This pre-compile is part of Nitro 3.1.0 and was added to our fork of Go Ethereum in Add Precompile for secp256r1 conditionally based on ArbOS version by anodar · Pull Request #303 · OffchainLabs/go-ethereum · GitHub and has been upstreamed into Nitro 3.1.0. Nitro 3.1.0 is the minimum supported version of Nitro for ArbOS 31 “Bianca”.

3. Update all Nova fund distributors to use a series of “fee routers” instead, while keeping the final destination as the ArbitrumDAO Treasury

Today, the ArbitrumDAO’s portion of the transaction fees from Arbitrum Nova are sent to the Core Governance L1 Timelock address, which is accessible via the

... please visit link below to view full proposal

https://tally.xyz/gov/arbitrum/proposal/108288822474129076868455956066667369439381709547570289793612729242368710728616