A primer on the blockchain written in Dec. 2014 by the creator of bit gold, a framework for a crypto currency with striking similarities to Bitcoin and that preceded it, as pointed out in this recent New York Times article speculating on the true identity of Bitcoin creator Satoshi Nakamoto.
Interestingly, the time stamp on the bit gold post is Dec. 27, 2008, nearly two months after the first paper describing Bitcoin was published to the Cryptography Mailing list on Nov. 1, 2008. In fact, the Times, citing the Internet Archive, claims Szabo first published the bit gold post on Dec. 29, 2005, nearly three years before the Bitcoin paper appeared. Szabo then republished his original article, according to the Times, to make it appear as if he had published it for the first time only after Bitcoin was already out in the open.
Further reading: Nick Szabo’s Web page listing his “essays, papers and concise tutorials.”