A Decentralized Oracle Network Constructed From Weighted Schnorr Multisignature

Abstract

A decentralized oracle network is a good solution for blockchain interoperability, and a multisignature is a proper cryptographic primitive for off-chain aggregation where each participating signer’s public key can be identified during verification. An important requirement for the decentralized oracle network is that some important data requests may require high-reputation nodes to validate the external data, while some common data requests may need only low-cost nodes to execute the validation. Thus, we present a weighted Schnorr multisignature to meet this requirement, which is proven to be unforgeable. However, purely relying on the cryptographic scheme cannot fully identify each participating node’s reputation; thus, we design three on-chain contracts for recording and identifying the oracle nodes’ reputation and realizing the reword mechanism. The on-chain components (e.g., smart contracts) and the off-chain components (e.g., oracle nodes) constitute a whole blockchain interoperability system. We implement our system over the Ethereum platform and analyze its on-chain and off-chain costs.