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:

https://en.wikipedia.org/wiki/Merkle%27s_Puzzles

If someone could link me to the paper in question, I would really appreciate it.

A little late, but I believe this is the paper mentioned: https://socrates1024.s3.amazonaws.com/consensus.pdf