Table of Contents

Summary

• The Uniswap DAO uses cross-chain messaging protocols (bridges) to relay governance decisions from Ethereum to destination chains where the Uniswap V3 contracts have been deployed. The functional and non-functional requirements of this use case are defined below.
• Bridges are complex systems; the Uniswap Foundation’s Bridge Assessment Committee developed a framework to evaluate them in the context of the DAO’s use case.
• The Committee evaluated six bridges and approved two for the DAO’s cross-chain governance use case; the others will be reviewed again in the coming months as warranted by their continued development.
• The Committee determined that a multi-bridge architecture was likely the best option for the Uniswap DAO’s cross-chain governance use case, but noted that protocols that provide this functionality are nascent and not mature enough for immediate implementation. The Committee provided recommendations for the continued development of multi-bridge cross-chain messaging architecture.
• The Committee made several implementation recommendations that could be put into effect presently to improve the security of Uniswap's existing cross-chain deployments.
• The Foundation intends for this to be the first of many reports regarding cross-chain governance as well as the first set of bridge assessments; follow-on grants are planned for both continued long-term research and development and ad hoc bridge assessments and re-assessments.

Introduction

On December 11, 2022, the Uniswap forum received a proposal to officially deploy Uniswap v3 on BNB Chain, which garnered community support. The discussion quickly shifted to the issue of which bridge protocol would be used for cross-chain governance purposes. Over the course of nearly 100 posts, community members presented Celer, DeBridge, Wormhole, and LayerZero as potential options. The conversation was deeply technical and sometimes contentious, with various bridge team members weighing in directly on the costs and benefits of each proposed solution.

https://app.uniswap.org/#/vote/2/31

The proposal eventually passed, and Uniswap was deployed on BNB Chain using Wormhole as the governance bridge. The discussion preceding the vote made it clear that cross-chain messaging and the protocols that enable it occupy a nascent and complex design space. It is not practical to expect the typical Uniswap governance delegate to understand the intricacies of each bridging solution presented, particularly when the designs and implementations are themselves not static. A further complication for delegates are the sources of information on bridges; delegates who are not deeply versed in the nuances of cross-chain messaging may be forced to trust sources that are biased in their views.

In the wake of the BNB Chain vote, and to better prepare the Uniswap community for making this type of decision going forward, the Uniswap Foundation convened a Cross-chain Bridge Assessment Committee to produce the following report. The goals of the Committee, as defined in the governance forum post discussing its formation, were:

• Support delegates and community members in making informed decisions related to cross-chain deployments
• Provide process clarity to bridge providers
• Remove inefficiency in the governance process moving forward for all governance stakeholders.

The Foundation believes that this report accomplishes all three goals by defining bridge providers that have been assessed as suitable for Uniswap’s cross-chain governance use case, publishing the framework by which those assessments were made, and providing a basis for discussion between stakeholders when evaluating governance proposals that involve cross-chain messaging.

Going forward