Thats the point Adam is making. "Anyway I claim the hard part about bitcoin is the decentralised secure inflation control (and sybil resistant byzantine generals solution.) "
And I strongly disagree with that point. The inflation control is not the interesting part at all. Without decentralization, inflation control is not a problem at all. It is the decentralization that makes the big difference from previous digital monies.
You might need to tune some stuff - eg the identities must be timestamped, time-limited use etc but probably you could make that work.
What does time even mean if you don't have the block chain or a central authority?