Abstract
Data cooperatives allow their members—the data owners—to pool their digital assets together for processing and access management. In this context, reputation is an important measure of trust, which can effectively complement financial assets in the decentralized scenario, also providing incentives for users’ honest behavior. We present a decentralized data cooperative system based on the Proof-of-Reputation and Proof-of-Stake blockchains. In order to provide inclusivity for low-reputation (newly joined) users, which is required in our community-based scenario, we use the tier-based committee selection introduced by Kleinrock et al. at Indocrypt 2020. As the underlying Proof-of-Stake system, we use Snow White due to its convenient properties such as flexible committee selection and user participation.