I believe that I responded to that paper at least once. By my memory, the formalization of Bitcoin's security left room for a polynomial time attack on the system. That is a fine restatement of what we already know about Bitcoin, but:
1. It is irrelevant to this thread, because I was only talking about Satoshi's paper.
2. It is not the sort of security people demand out of other cryptosystems. There is a reason nobody uses this: