Embedding a Deterministic BFT Protocol in a Block DAG

ABSTRACTThis work formalizes the structure and protocols underlying recent distributed systems leveraging block DAGs, which are essentially encoding Lamport's happened-before relations between blocks, as their core network primitives. We then present an embedding of any deterministic Byzantine fault tolerant protocol ℘ to employ a block DAG for interpreting interactions between servers. Our main theorem proves that this embedding maintains all safety and liveness properties of ℘. Technically, our theorem is based on the insight that a block DAG merely acts as an efficient reliable point-to-point channel between instances of ℘ while also using ℘ for efficient message compression.