We should build cross-chain solutions as if consensus mechanisms are not necessary – because they are. Blockchain technology is being praised for its potential to revolutionize various industries through decentralization, security and transparency. However, as the ecosystem expands, the complexities and costs associated with interoperability between different blockchains are becoming increasingly apparent.
Consensus algorithms are essential for individual blockchain networks, ensuring that all participants agree on the state of the ledger to maintain its integrity and security. But when these mechanisms are applied to interoperability solutions such as cross-chain bridges, they introduce significant inefficiencies and risks.
Implementing interoperability consensus often leads to extreme over-collateralization – sometimes more than 100 times the value of the assets transferred. Funds are locked into validator nodes to secure the network, tying up huge amounts of capital. For example, a common bridge pays each validator approximately $30,000 per month, which amounts to a staggering $3 million per month for their 100 validators. The additional costs of fostering and maintaining a community of validators only adds to this financial burden.
Read more in our opinion section: Don’t let Web3 repeat Web2’s interoperability mistakes
This over-collateralization is not only expensive; it is economically inefficient. Total value locked (TVL) is often emphasized in the DeFi space. But when it comes to bridges, these numbers often mask these underlying inefficiencies by presenting them as indicators of success rather than sunk costs. While consensus is intended to provide security, it does not guarantee consistency in interoperability solutions.
Bridges introduce non-deterministic data, meaning that the same input does not always produce the same output in different chains. Without consistency, the stability of the entire system decreases with each additional connected blockchain. This instability increases the risk of tokens or transactions being duplicated, stuck, or disappearing altogether. It is estimated that billions of dollars have been stolen from bridges, including $650 million from Ronin, $326 million from Wormhole and $566 million from Binance’s BNB Chain bridge.
The lack of consistency also hinders DeFi’s abstractions and composability. Bridges often rely on hardcoded primitives that require hard forks to modify, complicating innovation and slowing the evolution of dapps. Many interoperability solutions are difficult to scale effectively. Because these bridges can be thought of as blockchains, with their own consensus mechanisms, they introduce additional layers of complexity and potential bottlenecks. This not only slows down transaction times, but also adds more points of failure to the system.
Read more in our opinion section: Blockchains are still not good at communication
The bottom line is simple: consensus mechanisms are not necessary for interoperability and can even be counterproductive. By eliminating the need for consensus in cross-chain solutions, we can significantly reduce costs and complexity. Instead of relying on validators to maintain a consensus, we can use deterministic proofs and verification methods that are inherently secure and efficient.
The key to enabling consensusless interoperability is moving proof and verification mechanisms out of layer-1 smart contracts. This approach resolves major bottlenecks, such as the limited availability of data across the chain. By decoupling from individual layer 1 restrictions, dapps can process data more freely and create additional value without being hampered by consensus-related restrictions – which benefits not only blockchains, but most importantly their users.
Read more in our opinion section: Interoperability is not just a buzzword
By focusing on deterministic computation, interoperability solutions can ensure transactions are predictable and verifiable without the overhead of consensus mechanisms. Techniques such as referenced delegation of computation (RDoC) and cryptographic validation provide the necessary security guarantees. This approach reduces the risk of inconsistencies and errors, improving the overall stability of cross-chain interactions.
Removing consensus on interoperability is not just a cost-saving measure; it is a strategic evolution in building blockchain networks. This paradigm shift allows for greater levels of abstraction, improved efficiency and more room for innovation. Developers can create more complex and composable dapps without being hampered by the limitations imposed by consensus-based bridges.
The current reliance on consensus mechanisms for interoperability is both costly and inefficient. By rethinking our approach and eliminating unnecessary consensus layers in cross-chain solutions, we can build a more robust, scalable, and efficient blockchain ecosystem. This strategic move not only reduces operational costs, but also fosters innovation, allowing blockchain technology to reach its full transformative potential.