After months of development we are excited to see the Arbitrum team make their Layer 2 solution, Arbitrum One, available publicly on mainnet. This Optimistic rollup will facilitate the mass scaling of Ethereum and EVM compatible smart contracts by reducing transaction costs and latency. Optimistic rollups make this possible by minimising the amount of on-chain data by rolling up data into a cryptographically hashed transaction to reduce the required computation on base layer Ethereum.
Similarly to our previous work done with Optimism, The MakerDAO Protocol Engineering Core Unit have been busy working alongside Arbitrum and now that Arbitrum is launched on mainnet, we will conduct a final internal audit of the Custom DAI Gateway before officially launching on Arbitrum mainnet. From the risk perspective Arbitrum One is fundamentally very similar to Optimism’s rollup. Even though the architecture warrants a similar approach, there are some implementation-level differences regarding L1→L2 message passing, the fraud proof system, etc, that require this final review.
Why Custom DAI Gateway ?
Many DeFi projects, upon launch, will use a Standard Arbitrum Gateway to move their tokens to L2. As explained in the MakerDAO Multichain Strategy we consider this approach to be somewhat limited if we want to then allow direct minting of DAI on L2 and make this minted DAI fungible with DAI bridged from L1. Having this long-term goal in mind, similarly to Optimism we have decided to opt out from using a Standard Arbitrum Gateway and are developing a simple Custom DAI Gateway. This way MakerDAO governance will be the only authority that will be allowed to upgrade this Gateway in the future to both enable fast withdrawal schemes and DAI minted on L2.
The Protocol Engineering Core Unit is expecting to launch our Custom DAI Bridge within the coming weeks as soon as we are finished with all internal audits of our code and external audits of Arbitrum code upon which the gateway is built are ready for public review. This is critical to ensure the custom gateway is safe and secure for DAI users.