Abstract: A blockchain-based, decentralized data marketplace is described. The marketplace allows data sellers to sell their data to data buyers in exchange for payments in tokens. The marketplace allows for securely and anonymously selling data in a trusted environment that is also fair to all participants and provides data sellers with the ability to control and monetize their own data (e.g., personal data). A notary with access to “ground truth” data can validate data that is being offered in the marketplace to ensure that it is not falsified or fabricated before it is purchased by a data buyer. The marketplace implements blockchain-based smart contracts that work together, and with cryptographic protocols, to achieve an efficient, decentralized data marketplace where data sellers and data buyers transact directly with one another while remaining anonymous, if desired.

Abstract: Users can be classified as belonging to one of multiple income categories. A communications graph can be generated based on call data records (CDRs), the graph including a subset of nodes representing users of a mobile telephony network whose income is estimated based on available banking records. For a node representing a user whose income is unknown (i.e., a node that is not within the subset of nodes), and which is connected by a link to at least one node within the subset of the nodes, a Bayesian prediction algorithm may be used to classify the selected node. The Bayesian prediction algorithm may include defining a prior probability distribution of a Bayesian inference with a parameter based on a number of outgoing communication sessions from the selected node to nodes associated a particular income category, and computing a value for a lowest Nth percentile of the prior probability distribution.