Blockchain: Distributed Event-based Processing in a Data-Centric World: Extended Abstract.

Usage of Blockchain is expanding from the initial focus on crypto-currencies towards applications to support a broad range of collaborative activies amongst businesses, organizations, and individuals. There are two broad levels of Blockchain: the foundation level relates to encryption, consensus algorithms, and support for a single (logical) data store that is shared by all participants; and the \"smart contract\" level that enables developers and business-level users to specify the data, logic, and behavior that collaborations should follow. The smart contracts are programs that are fundamentally event driven, data-centric, and support the activity of a distributed set of stakeholders situated across multiple organizations. This raises an array of research challenges in areas including language and solution design, interoperation across smart contracts, and verification.