DARPA engaged cybersecurity research and consulting firm Trail of Bits to examine the fundamental properties of blockchains and the cybersecurity risks associated with them. Trail of bits investigated the extent to which blockchains are truly decentralized. They focused primarily on the two most popular blockchains: Bitcoin and Ethereum. They also investigated proof-of-stake (PoS) blockchains and Byzantine fault tolerant consensus protocols in general. This report provides a high-level summary of results from the academic literature, as well as their novel research on software centrality and the topology of the Bitcoin consensus network. For an excellent academic survey with a deeper technical […]