Adam Back, the cryptographer and chief executive of blockchain technology company Blockstream, has pushed back against claims that he is Satoshi Nakamoto, the pseudonymous creator of Bitcoin, but his defence rests on arguments that do not withstand close scrutiny.
Back has offered three grounds for dismissing the suggestion: that chat logs from 2013 show him still learning how Bitcoin worked two years after Satoshi went silent; that sharing private emails without the other party's consent is a matter of basic courtesy; and that it is simply impossible to disprove a claim people have already decided to believe.
The learning curve argument is the most specific of the three, and the most superficially convincing.
If Back had designed the system, the reasoning goes, he would not have needed to ask developers how it functioned.
But Satoshi disappeared from public view in April 2011, and a person who had operated anonymously for years, and who understood the consequences of exposure better than anyone, might plausibly have chosen to re-enter Bitcoin discussions presenting as a curious newcomer rather than an authority.
Asking basic questions in 2013 could reflect calculated caution as easily as genuine ignorance.
The email argument is where Back's position becomes hardest to sustain.
New York Times investigative journalist John Carreyrou asked Back to release metadata from the emails Satoshi sent him before the Bitcoin white paper was published in 2008; Back declined, citing the impropriety of sharing private correspondence without the other party's permission.
That reasoning might carry weight if the other party were reachable.
Satoshi Nakamoto is a pseudonym attached to a person who has been untraceable for 14 years, and Back cannot seek consent from someone who, by design, cannot be found.
Back has also acknowledged sharing the same emails with lawyers acting on behalf of Bitcoin developers when asked to do so, a distinction he drew at the time that sits uneasily with the position he is now taking.
Carreyrou's case, built on writing patterns, timing, and the significance of Back being the first person Satoshi ever contacted before publication, is circumstantial and falls short of proof.
Back is correct that disproving a negative is difficult, and that determined believers are rarely shifted by counter-argument alone.
Both observations are reasonable in the abstract, and both are also precisely what someone in his position would say regardless of whether the underlying claim is true.
The metadata would settle more than anything Back has offered so far, and he has declined to provide it.