Consensus is the problem of agreeing on a valid input value among members of a distributed system. Internet-level consensus scales the concept to global agreement, despite the fact that the Internet has no meaningful notion of membership. Global consensus is a powerful tool, enabling atomic transactions across mutually distrustful parties with no prior relationship. Such transactions facilitate many applications from Internet payments to binary transparency. Though any given person cares primarily about consensus among a few dozen organizations--e.g., an employer, trading partners, trusted certificate authorities--no single such set of organizations can possibly satisfy the whole Internet's security needs.
In this talk David presents federated Byzantine agreement (FBA), a new consensus model suitable for settings without global agreement on trusted authorities. FBA is the basis of the Stellar consensus protocol (SCP) in use by the Stellar payment network.