Working through it now -- lets say I am rapidly heading towards "Not a hoax" territory.
[Edit: Or, possibly, totally quackadoodle -- but very convinced-in-himself quackadoodle. I've gotten as far as proving "OK, he knows how to reverse a Bitcoin address into a public key, and picked a good address for the purpose."]
I consider the posts by others of this thread of a Bitcoin transaction with the same signature to be dispositive that he was not signing any variant of the Sartre message.
Conclusion: a) The linked blog post is pure hokum. b) I'm very clear on how he got this past generalist media but unsure of how he got it past Gavin.
He's making all this up. Unless the message signed contains Craig Wright's name it's not proof of anything.
Yeah, but I can do that. Can it be my turn to be Satoshi now? It's specialized knowledge only insofar as you need to have read how to do it and understand enough to write some commensurate code. This is widely-published stuff. It doesn't take a Satoshi or even an expert.