Classifying Cross-chain Bridges Part 2: Consensus

In the first part of the series, we covered various execution mechanisms of cross-chain bridges with their own trade-offs. In this second part of the series, we explore how bridges can be classified by their consensus mechanisms.

During a cross-chain transfer, a bridge must inspect and acknowledge that assets are securely in escrow on the origin chain before releasing funds on the destination chain. The consensus aspect of a bridge refers to how such an acknowledgment is reached and verified. A flawed consensus could become an attack vector for withholding or stealing users’ funds.