Following waves made by Australian tech entrepreneur Craig Wright saying on Monday that bitcoin founder Satoshi Nakamoto was his alter-ego, doubts on the validity of his claim have emerged from prominent corners of the cryptography community.

"There’s no way you can conclusively prove that you are the creator of bitcoin," said Jerry Brito, executive director of Coin Center, a crypto-currency think tank in Washington DC skeptical of Wright’s claims.

Stronger proof needed

The think tank also indicated Wright’s technical demonstration using Nakamoto’s secret bitcoin keys may not have been the strongest way to prove he invented the cryptocurrency.

The Coin Center’s director of research Peter Van Valkenburgh said it would have been more convincing if Wright sent a new message cryptographically signed using the private key associated with the first ever bitcoin block "mined" - the so-called Genesis block.

In contrast to paper currency which is printed and distributed by a central government authority, bitcoins are "mined" with special software which issues the cryptocurrency in exchange for solving difficult math problems.

Wright indifferent to non-believers

Wright himself has expressed little interest in converting skeptics.

A screenshot of Craig Wright's personal website

"I was the main part of it, other people helped me," Wright told British broadcaster BBC. "Some people will believe, some people won’t and to tell you the truth, I don’t really care."

But the camp of believers has its own share of prominent names, like Gavin Andresen, chief scientist of the Bitcoin Foundation. Andresen said Wright convinced him "beyond a reasonable doubt" that the Australian was indeed Nakamoto, as the two met privately in London.

David’s revelation came five months after tech websites Wired and Gizmodo published evidence that indicated he was behind bitcoin, and after police raided his home in Sydney. In Australia, regulators have ruled that bitcoin should be considered an asset, rather than a currency, for taxation purposes.

The use of bitcoin still throws up regulatory questions

Observers estimate that whoever invented bitcoin may hold up to one million of more than 15 million bitcoins in circulation, currently worth around $440 million (379 million euros).

Will the real Mr Nakamoto please stand up?

Before the Wired and Gizmodo reports, speculation as to the bitcoin founder’s identity centered on several figures in the currency’s eight year history, including the Bitcoin Foundation’s Andresen.

But it was the similarly-named Japanese-American engineer Dorian Satoshi Nakamoto who found himself in the center of a media frenzy in 2014 after a Newsweek magazine article identified him as bitcoin’s possible founder.

The latest twist in the saga surrounding bitcoin’s origins comes at a time when a debate is raging between those who want to see it expand into a more mainstream payment and investment tool, and those who want to keep it small and alternative - a central issue of the digital currency’s future, which may just outlast questions of its past.

jd/uhe (Reuters, AFP, AP)