Now we may never know whether Craig Wright is indeed mysterious Bitcoin founder Satoshi Nakamoto.

In a reversal from a promise the Australian computer scientist gave two days ago to provide “extraordinary proof” that he created the Bitcoin cryptocurrency in 2009, Wright replaced his blog site today with an online apology letter – titled “I’m Sorry” – which says, “I know now that I am not strong enough for this.”

I believed that I could do this. I believed that I could put the years of anonymity and hiding behind me. But, as the events of this week unfolded and I prepared to publish the proof of access to the earliest keys, I broke. I do not have the courage. I cannot.

When the rumors began, my qualifications and character were attacked. When those allegations were proven false, new allegations have already begun. I know now that I am not strong enough for this.

I know that this weakness will cause great damage to those that have supported me, and particularly to Jon Matonis and Gavin Andresen. I can only hope that their honour and credibility is not irreparably tainted by my actions. They were not deceived, but I know that the world will never believe that now. I can only say I’m sorry.

And goodbye.

Dr. Craig Wright, who may or may not be the creator of Bitcoin – we may never know!

Monday, articles published by the BBC, GQ, and the Economist included interviews with Wright in which he officially claims be the creator of Bitcoin. The “admission” came after rumors had been floating for months that Wright was the man behind the pseudonym Satoshi Nakamoto, the name under which the original Bitcoin software was released. The claimed founder of the currency also said that computer security expert and author Dave Kleiman, who died in 2013, gave him “extensive help” in creating it.

Though Wright’s claim, at the time of announcement, was publicly backed by Gavin Andresen, chief scientist at the Bitcoin Foundation, and Jon Matonis, founding director of the Bitcoin Foundation, Andresen offered a backtracking statement one day later, saying, “I was as surprised by the ‘proof’ as anyone, and don’t yet know exactly what is going on.” Many experts are unconvinced that the “evidence” Wright provided Monday, an early Bitcoin signature, is any evidence at all that he is Nakamoto.

“It was a mistake to agree to publish my post before I saw his,” Andresen wrote in an email now posted to security expert Dan Kaminsky’s blog. “I assumed his post would simply be a signed message anybody could easily verify.”

Having now said he will not provide any further proof that he is Nakamoto, the Craig Wright doubters have been given fresh meat upon which to nosh. The “Find Satoshi game” that Andresen is now commiserating over his participation in may not be finished. But the Craig Wright chapter seems all but ended – at the moment.

Photos via Wikipedia, George Frey / Stringer / Getty