I dont think there's any way to know if this is real for sure. The paper however has a lot of details on the birth of bitcoin, lending some credibility to author's claim.
I would rather believe Craig is Satoshi than this one is. At least Craig sounds more Satoshi-like. Though I won't believe anyone who doesn't prove it with a signed message.
What makes Craig sound like Satoshi?
He doesn't necessary sound like Satoshi, but his style of writing is closer to Satoshi's than this Duality paper.
