# \[Discussion\] \[OBRA\] Cross-Chain Signers Synchronization for Multi-sig Wallets **URL:** \ **Category:** Archive\ **Created:** [September 18, 2024, 3:16pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742 "2024-09-18T15:16:59Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![vadimicus](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/vadimicus/32/3996_2.png) [@vadimicus](https://forum.safefoundation.org/u/vadimicus)\ **Post date:** [September 18, 2024, 3:16pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/1 "2024-09-18T15:16:59Z")
_**[Discussion] Cross-Chain Synchronization for Multi-sig Wallets**_ _ **Authors** _: - Vadim Makovsky ([vadim.makovsky@gmail.com](mailto:vadim.makovsky@gmail.com), telegram: [@vadimicus](https://t.me/vadimicus), x: [@vadimicus](https://x.com/vadimicus)) - Nikita Kaskov ([mail.nikita.kaskov@gmail.com](mailto:mail.nikita.kaskov@gmail.com), telegram: [@nkaskov](https://t.me/nkaskov)) - Mikhail Voronov ([michail.vms@gmail.com](mailto:michail.vms@gmail.com), x: [@vms11](https://x.com/vms11)) _ **Created** _: 2024-08-28 _ **Abstract** _ This proposal introduces a new approach to creating and managing multi-sig wallets across different Layer 2 (L2) networks, enhancing the user experience. When the configuration of the master wallet on the Ethereum blockchain is changed, the corresponding changes of the owners set are automatically across all dependent wallets on the L2 networks. The update process requires a valid zk-proof to confirm the new signers. The final solution will include a ready-to-use safe module, along with full-cycle integration into the proving protocol, covering proof building and verification. _ **Proposal types** _ Other SEPs _ **Proposal details** _ **Purpose and Background** This proposal aims to enhance the user experience in managing cross-chain multi-sig accounts. Currently, when users want to change a signer in such a wallet, they must manually create, sign, and approve the same transaction across all blockchains or rollups where the wallet exists. This process requires the presence and action of all signers throughout and incurs gas fees on each blockchain or rollup. This initiative proposes using a zero-knowledge proof approach to propagate updated signers across all protocols with a single action. **Effects and Impact Analysis** **Pros:** - Provides a reliable synchronization method that improves user experience. - Reduces the risk of human error. - Advances in the development of omni-chain architecture. - Requires less or the same amount of gas. **Cons:** - Requires an additional module. **Risks:** - The Modules allowed to modify Owners set have the highest access level to the Safe account, so a proper audit is crucial. - Implementation complexities due to the different configurations of the Safes. **Implementation** In the context of the interchain sync, there is a master chain (the preferable options are the Gnosis Chain and the Ethereum Mainnet) and several follower chains (such as Arbitrum, Polygon, and others). The trustless sync mechanism will consist of several parts: - The off-chain indexer of the master chain - The off-chain zk-proving part (includes the multi-sig verification circuit) - The endpoints on the follower chains **Integration with the Safe contracts** The integration with the Safe contracts will be done through a Safe module that will manage the zk-proof verification and trigger Safe’s OwnerManager to apply the verified changes in the multi-sig configuration. _ **Open Questions** _ We can implement the module in three different ways, and each will require a different amount of resources. - Separate module - A Zodiac module - A Safe module _ **Funding Request** _ **Separate module** $45,000 = $35,000 core functionality + $10,000 UI part **A Zodiac module** $35,000 **A Safe module** $35,000 _ **Upfront Funding** _ Ideally, 100% in order to fund the audit. Can do in installments of 50% as well. _ **Metrics and KPIs** _ > 🧭 We are working on Dune visualization and are going to add it in this section before the start of voting for the proposal - Number of manual transactions changing the Owners set on follower networks - Number of Successful Account Synchronizations - User satisfaction rating - Security incidents reported _ **Timeline and Milestones** _ **Phase I. Proving in testnets** - 7 weeks: Design and implementation of the threshold multi-sig verification circuit - 4 weeks: Implementation of indexers and provers. Provers management CLI development. - 2 weeks: Deployment of testnet follower chains verifiers. Integration of verifiers with the testnet Safe contracts. **Phase II. Distributed proving in testnets** > 🧭 _Duration of this phase depends on how the module will be presented to the end users._ - 3 weeks: Implementation of intermediate verification strategies and fault-tolerance algorithms of proof aggregation. - **Separate module** - **A Zodiac module** - **A Safe module** _ **Phase III. Distributed proving in mainnet** _ The timelines of this phase will depend significantly on the security audit, so for now, we will only describe the intermediate steps. TBD (est. 5 weeks): Deployment of the mainnet follower chains verifiers and integration of the verifiers with the mainnet Safe contracts. _ **Team** _ - Vadim Makovsky - Email: [vadim.makovsky@gmail.com](mailto:vadim.makovsky@gmail.com) - Github: [@vadimicus](https://github.com/vadimicus) - Telegram: @vadimicus - x: @vadimicus - Nikita Kaskov - Email: [mail.nikita.kaskov@gmail.com](mailto:mail.nikita.kaskov@gmail.com) - Github: [@nkaskov](https://github.com/nkaskov) - Telegram: @nkaskov - Mikhail Voronov - Email: [michail.vms@gmail.com](mailto:michail.vms@gmail.com) - Github: [@mikevoronov](https://github.com/mikevoronov) - x: [@vms11](https://x.com/vms11) _ **Copyright** _ Copyright and related rights waived via CC0. Code open source with MIT license. ---
**Author:** ![amanwithwings](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/amanwithwings/32/3997_2.png) [@amanwithwings](https://forum.safefoundation.org/u/amanwithwings)\ **Post date:** [September 23, 2024, 10:45am UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/2 "2024-09-23T10:45:22Z")
Hey @vadimicus, thank you for taking the time to submit this proposal. Your proposal will be evaluated in Season 4 / Sprint 1. For more details on timelines, please check out this [post](https://forum.safefoundation.org/t/season-4-timelines/5732). Action items: None for now. ---
**Author:** ![nebula](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/nebula/32/4025_2.png) [@nebula](https://forum.safefoundation.org/u/nebula)\ **Post date:** [October 2, 2024, 5:45pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/3 "2024-10-02T17:45:18Z")
Hi @vadimicus! Could you elaborate more about potential risks involved? Very curious ---
**Author:** ![vadimicus](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/vadimicus/32/3996_2.png) [@vadimicus](https://forum.safefoundation.org/u/vadimicus)\ **Post date:** [October 3, 2024, 2:04pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/4 "2024-10-03T14:04:47Z")
Sure, thank you for your question! There are limited risks. In addition to those already mentioned in the proposal (e.g., the modules allowed to modify the owners set have the highest access level to the Safe account, making a proper audit essential; and implementation complexities due to the different Safe configurations), there are general risks associated with ZK, specifically: - Risks related to incorrect execution of the setup ceremony - Risks stemming from an incorrect choice of security parameters However, it’s important to note that these are theoretical risks tied to the use of ZK proofs, and they can be fully mitigated through correct implementation of the proving mechanisms. This will be ensured through thorough audits, which are already part of the proposal’s plan. In summary, we can mitigate all these risks by adhering to well-established security protocols. ---
**Author:** ![nebula](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/nebula/32/4025_2.png) [@nebula](https://forum.safefoundation.org/u/nebula)\ **Post date:** [October 3, 2024, 8:19pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/5 "2024-10-03T20:19:39Z")
Thank you for your reply @vadimicus! Looks reasonable. Also, another question: How would you describe a good use case for your solution? ---
**Author:** ![vadimicus](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/vadimicus/32/3996_2.png) [@vadimicus](https://forum.safefoundation.org/u/vadimicus)\ **Post date:** [October 4, 2024, 12:57pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/6 "2024-10-04T12:57:42Z")
Thank you for you questions @nebula One obvious use case is family offices and funds. Imagine a multi-sig that requires signatures from 7 partners. With the current Safe solution, if you’re working across three different chains, you’d need a total of 21 signatures. Coordinating that, especially across different time zones, can be challenging. Our solution simplifies this by reducing the number of actions needed—just one signature from each participant. This: - Significantly improves the user experience (less coordination needed) - Lowers costs by reducing transaction fees. ---
**Author:** ![nebula](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/nebula/32/4025_2.png) [@nebula](https://forum.safefoundation.org/u/nebula)\ **Post date:** [October 5, 2024, 12:38pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/7 "2024-10-05T12:38:13Z")
Thank you @vadimicus, this makes sense. No more questions from my side yet ---
**Author:** ![Hopper](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/hopper/32/4090_2.png) [@Hopper](https://forum.safefoundation.org/u/Hopper)\ **Post date:** [October 7, 2024, 7:15am UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/8 "2024-10-07T07:15:23Z")
Hey @vadimicus, I believe our teams could have great synergy. I’m creating a Telegram group to discuss it further. ---
**Author:** ![vadimicus](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/vadimicus/32/3996_2.png) [@vadimicus](https://forum.safefoundation.org/u/vadimicus)\ **Post date:** [October 7, 2024, 1:13pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/9 "2024-10-07T13:13:08Z")
Thank you! Let’s chat! ---
**Author:** ![cameronraysmith](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.safefoundation.org/cameronraysmith/32/4162_2.png) [@cameronraysmith](https://forum.safefoundation.org/u/cameronraysmith)\ **Post date:** [December 7, 2024, 11:45pm UTC](https://forum.safefoundation.org/t/discussion-obra-cross-chain-signers-synchronization-for-multi-sig-wallets/5742/10 "2024-12-07T23:45:10Z")
Adopting this proposal will provide a significant improvement in Safe UX. Thank you!