Sherman, Alan T.Javani, FaridZhang, HaibinGolaszewski, Enis2018-12-182018-12-182018-10-15http://hdl.handle.net/11603/12304We explore the origins of blockchain technologies to better understand the enduring needs they address. We identify the five key elements of a blockchain, show embodiments of these elements, and examine how these elements come together to yield important properties in selected systems. To facilitate comparing the many variations of blockchains, we also describe the four crucial roles of blockchain participants common to all blockchains. Our historical exploration highlights the 1979 work of David Chaum whose vault system embodies many of the elements of blockchains.14 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.blockchaincryptographydavid chaum’s vault systemdigital currencydistributed ledger technology (DLT)cryptographic hashingproof-of-workUMBC Cyber Defense LabText