Consensus Model Trade-offs for Interoperability: PoW, PoS, DPoS, and BFT in Cross-Chain Bridge Security
Over $2.3 billion was drained from cross-chain bridges in the first half of 2025 alone—already surpassing the full-year total from 2024. While much of the industry conversation focuses on smart contract audits and multisig key management, a quieter but equally critical vulnerability often goes unexamined: the mismatch between how different blockchains reach consensus and how bridges assume they do.
Every cross-chain bridge makes implicit assumptions about finality. When those assumptions collide with the actual consensus model of a source or destination chain, attackers find windows to exploit. Understanding how PoW, PoS, DPoS, and BFT consensus mechanisms differ—and how those differences cascade into bridge design choices and messaging protocol selection—is one of the most important topics in Web3 infrastructure today.