Dr Wright says that he used his own Windows laptop which was also running a Linux virtual machine. Bitcoin Core was installed and the whole blockchain downloaded. Dr Wright claimed that he signed a message of a speech by Jean-Paul Sartre which was stored in a file named “Sartre.txt” using the private key corresponding to the public key used in the coin generation transaction in block 9. He cited the command (starting “bitcoin-cli”) which he used. He claimed that he then copied the signature across to the virtual machine and used a further command on the Bitcoin Core software to verify it.

As Prof Meiklejohn explained, it would have been simple to write programs to (a) output a random string in response to the signature command; and (b) output “true” in response to the verification command. Mr Gao agreed with her on these matters. Dr Wright did not dispute that evidence. There is no evidence that Mr Matonis or any of the journalists took any steps to prevent the session being staged in this way. Of course, Dr Wright now insists that he did not stage it, and that he inputted the full command path at each stage. However, there is no independent assurance of these matters. Given Dr Wright’s claimed expertise, if he had wanted to conduct reliable proof sessions, he could have done so very simply (most obviously by just handing over a signed message on a clean USB stick). Mr Gao readily agreed that that would have been simple, reliable and a process involving no risk of compromising the private key. As with the Sartre blog, Dr Wright adopted an over-complex process.

Prof Meiklejohn also noted that it is surprising, from a security perspective, for Dr Wright to have repeatedly connected his computer (containing these private keys) to the internet, given the ease of cold storage solutions. On his account, she was indicating that he took real security risks while adopting complex steps to avoid spurious risks.

In opening submissions, Dr Wright relied upon hearsay attributed to Mr Matonis in a press release of 28 April 2016 (i.e. before the debacle of the Sartre Blog post) suggesting that he was persuaded by the signing session he attended. This multiple hearsay statement was not even submitted under a CEA notice.

In the course of closing submissions, Dr Wright served a CEA notice dated 13 March 2024 relying on a blog post of Mr Matonis dated 2 May 2016 entitled ‘How I Met Satoshi’. In that blog post, Mr Matonis related his encounters with Dr Wright, culminating with ‘the London proof sessions’. Mr Matonis said ‘the proof is conclusive’. Although posted on 2 May 2016, that blog post must have been written in advance, so that it was released as part of the planned ‘Big Reveal’.

I am inclined to place very little weight on Mr Matonis’ blog post, not least because we have no idea whether subsequent events caused him to change his mind or dent his conviction. We do not know Mr Matonis’ reaction to the debacle of the Sartre blog. The dinner with Mr Hearn (see below) took place a couple of months later, at which time Mr Matonis seems to have been looking to Mr Hearn for confirmation of his view, something which indicates Mr Matonis was less sure of the position than when writing his blog. Equally, we do not know Mr Matonis’ reaction to what Mr Hearn said to him after the dinner. In any event, Mr Matonis has not given evidence. The agreed expert evidence is that his proof session could very easily have been faked. And it is telling that Mr Andresen was initially persuaded by the signing session he attended, but later came to believe that it could well have been spoofed.