…↑ Nakamoto, Satoshi (31 October 2008). "Bitcoin: A Peer-to-Peer Electronic Cash System" (PDF) . bitcoin.org. Archived (PDF) from the original on 20 March 2014 . Retrieved 28 April 2014 . ↑ Vigna, Paul; Casey, Michael J. (January 2015). The Age of Cryptocurrency: How Bitcoin and D…