ArkProject: NFT Bridge

Summary

The current bridge design for NFT collections on L1 and L2 chains places significant control in the hands of the bridge admin, particularly in transferring ownership of collections on the target chain (L2). This dependency on the bridge admin creates potential delays & centralization risks. Collection owners must rely on the bridge admin to transfer ownership before they can manage their assets on L2.

Impact

• Dependency on Bridge Admin: Collection owners are dependent on the bridge admin for transferring ownership, which can cause delays and potential misuse of power.

• Risk of Unauthorized Transfers: The bridge admin has the authority to transfer ownership to any address, posing a risk if the admin's actions are not transparent or securely managed.

• Lack of Autonomy for Collection Owners: Owners cannot independently manage their collections on L2 without first obtaining ownership, limiting their control and flexibility.

Proof of concept

• Let say Dandy is owner of Bored Ape Collection on L1 (ETH), he can manage all functionality of the collection on L2 e.g setting token uri, or base uri of the nfts

• Holders of Bored Ape Collection bridged to L2 for some reasons, during bridging new collection is created on L2. And on creation currently bridge is the owner of the Bored Ape Collection on L2 (Starknet)

• Now Dandy updated base uri or token uri on L1 for some reasons, but he can't update it on L2 instantly. For this he will have to request bridge admin to transfer ownership to him. This leads to temporary DoS here.

• Imagine a scenario where owner want to update the token uri for a specific event and he can't do it on L2 because he will have to request bridge admin to transfer ownership to him first then he can update it.

Recommendation

• Implement a Claim Ownership Feature: Introduce a feature that allows collection owners to claim ownership on L2 independently. This function should include a verification mechanism to ensure that only the rightful owner on L1 can claim ownership on L2.

• Verification Process: Use cryptographic proofs or signatures from the L1 contract to verify ownership before allowing the transfer on L2. This ensures that the process is secure and only legitimate owners can claim their collections.

• Autonomous Management: Allow the function to work in reverse (L2 to L1) as well, enabling owners to manage their collections across chains without relying on the bridge admin. This reduces centralization risks and improves the overall security and efficiency of the bridge.