DORA: Scalable Distributed Oracles by Aniket Kate

Connecting existing Web 2.0 data sources to blockchains is crucial for decentralized finance and beyond. An oracle network consisting of a network of independent nodes aims to address this issue by allowing blockchain smart contracts to function over inputs obtained from existing Web 2.0 data, real-world sensors, and computation interfaces. Performing this information exchange securely, however, is not trivial: most of the data sources today do not offer data in a signed form, the oracle network also becomes vulnerable due to the compromise of a subset of oracle network nodes; moreover, the adversary may go after the availability of the system (and at times safety) by malevolently slowing down the protocols. We address these issues, and propose a robust and scalable distributed solution for solving the oracle problem. While our approach (DORA) can withstand extreme adversarial settings, we make some real-world synchrony and input-data distribution observations, and introduce oracle execution sharing. In particular, having access to an ordering primitive such as state-machine replication (SMR), we can solve the decentralized oracle arrangement problem with only 51% honest nodes. This makes our solution scale quite well as the number of oracle services and the size of the oracle network grow. Aniket Kate