A ZK-based multi-blockchain transaction layer for minimal trust base

Abstract In the realm of blockchains, synchronization challenges are two-folded. First, smart contracts from different blockchains cannot communicate with each other, making it hard to establish a trustworthy communication channel to share and maintain a universal state between each other. Second, transactions on different blockchains can hardly be ordered. Hence interference is expected. We need a novel way to handle interference. Traditional solutions involving third parties have safety and liveness issues and thus compromise between safety, permissionless, and liveness. ZK Multi-Blockchain Aggregatoris a multi-blockchain execution layer that leverages the power of zero-knowledge proof to minimize the trust base of multi-blockchain communication, which does not compromise safety, liveness, permissionless, and atomicity. In contrast to traditional blockchain bridges performing transactions on different blockchains separately and using a relay system to enforce the order of transactions and prevent interference, our method uses an entirely new approach, such that for each multi-blockchain transaction, it simulates the multi-blockchain transaction in its aggregator chain. Our aggregator uses zero-knowledge proofs of the simulation to convince involved blockchains to update their local state accordingly. On top of this layer, rich applications over multi-blockchains can run safely and efficiently.