Bitcoin's self-proclaimed 'founder' backtracks
An Australian entrepreneur who came forward this week as the founder of digital currency Bitcoin appears to have backtracked on the claim.
Dr Craig Wright said in a blog post that he does not "have the courage" to publish additional proof, as promised, that he is the elusive creator of the currency.
Dr Wright said on Wednesday that he would provide additional proof to back up his assertion, which drew widespread scepticism.
Instead, he scrubbed his blog clean of past entries and posted a short statement entitled "I'm Sorry".
Dr Wright did not explicitly withdraw his claim to be Satoshi Nakamoto, Bitcoin's mysterious founder.
He wrote that he thought he could "put the years of anonymity and hiding behind me". But as this week's events unfolded, he wrote that he is "not strong enough for this."
"I can only say I'm sorry," he wrote at the end of the post. "And goodbye."
The search for Mr Nakamoto has been a parlour game for journalists and online sleuths since he disappeared from forums in late 2010.
Dr Wright claimed to be Mr Nakamoto in interviews with the Economist, BBC, GQ and a few Bitcoin insiders in stories published on Monday.
He bolstered the claim with technical demonstrations that two of the insiders vouched for, but failed to repeat the demonstrations in ways that could be verified by anyone else.
Sceptics reacted harshly to the public proof Dr Wright did offer.
For instance, he purported to sign a passage from Jean-Paul Sartre with one of Mr Nakamoto's private encryption keys.
Experts argued he had not done that at all, and instead had merely republished a snippet from a historical Bitcoin transaction signed by the original Nakamoto.
Other posts Dr Wright made following his revelation came under fire as well.
One of his blog posts attacked a 2013 paper that described how the Bitcoin system could be gamed by a group of insiders the paper called "selfish miners". Some readers of the post said it showed a fundamental misunderstanding of the risks.
"Sadly, Craig did not get it," said Emin Gun Sirer, a Cornell University computer science professor who co-authored the original paper.
"It seemed like he failed to understand what the whole attack was about. That completely made me doubt his veracity."