Multi-Signature and Game Based Blockchain Interoperability Oracle

To solve the problem of blockchain interoperability, we propose an efficient decentralization oracle solution. We design a subgroup Schnorr multisignature for the off-chain aggregation mechanism of our system, which is proven to be secure and robust. Compared with threshold signature-based schemes, the subgroup multisignature-based scheme does not require the execution of the distributed key generation protocol, which greatly reduces off-chain costs. The on-chain verification of the Schnorr signature is also more efficient than the pairing-based signatures. Then, we design a fair incentive mechanism to encourage the oracle nodes to work hard to validate the external data, which is based on a repeated dynamic game. Compared with the existing incentive mechanisms, our mechanism considers the real actions of each node to determine whether it should be rewarded or penalized. We implement our system over the Ethereum blockchain, and the experiments show its good performance.