Abstract
While Nakamoto’s protocol comes with answers to new and relevant questions in distributed systems, it also leaves open many challenging questions. In particular, optimizing and scaling consensus performance in terms of energy consumption, throughput, latency and storage in similar threat models as that of the Nakamoto’s blockchain protocol suggests an array of interesting research directions that have been recently pursued in a number of works inspired by this seminal paper. Relevant protocol techniques include proof of stake and the utilization of various cryptographic primitives such as verifiable random functions, key evolving signatures, coin flipping protocols, and others.