Wright is pretending he has Satoshi’s signature on Sartre’s writing. That would mean he has the private key, and is likely to be Satoshi. What he actually has is Satoshi’s signature on parts of the public Blockchain, which of course means he doesn’t need the private key and he doesn’t need to be Satoshi. He just needs to make you think Satoshi signed something else besides the Blockchain — like Sartre. He doesn’t publish Sartre. He publishes 14% of one document. He then shows you a hash that’s supposed to summarize the entire document. This is a lie. It’s a hash extracted from the Blockchain itself. Ryan Castellucci (my engineer at White Ops and master of Bitcoin Fu) put an extractor here. Of course the Blockchain is totally public and of course has signatures from Satoshi, so Wright being able to lift a signature from here isn’t surprising at all.