I am interested more in whether you can do it without a banking interface, but fully backed in bitcoins with full public auditability.. It seemed to me that this could work with the sequence of bootstrap via existing exchange for price feed, and then p2p self-contained market trading synthetic USD backed and hedged by BTC and BTC denominated options, the trade itself setting its own price.
ie once you had a bootstrapped exchange market in BTC with synthetic USD (itself constructed from BTC denominated synthetic USD futures) the only thing you lose if someone shuts off the conventional exchange is the possibility to do arbitrage between the BTC<->synthetic USD market and the BTC<->USD market?
ie the external cash in and cash out would be missing other than bitcoin OTC, but people with synthetic USD positions (still fairly closely tracking USD modulo missed arbitrage price synchronization) would be able to create new positions and liquidate existing positions and spend BTC and synthetic USD.
Adam
I think your idea is quite similar to the bitshares proposal.
I am not sure, if you are suggesting that when the price feed is switched off, that the synthetic USD will still be tracking the real USD. There was a similar very long discussion in the bitshare thread a while ago.
I think you cannot be sure how stable the price tracking will continue when the price feed is gone. Actually, after the connection between synthetic USD and real USD is gone, the synthetic USD price will be uncoupled from the real USD and would move up or down depending on how many people think it will go up or down: so in other words, the price of synthetic USD will be freely floating away from the real USD.
You might argue that it will still track the real USD price because of arbitrage traders, but that is a circular argument where you assume that arbitrage traders think it will continue to track the real USD price. Actually some very rich person might make a lot of money by short selling synthetic USD until it is obvious for all arbitrage traders that the synthetic USD will not track the real USD. This could then continue in a downward spiral until sythetic USD is worth nothing.
So, to sum up, I think it will not work if you shutdown the price feed from a conventional exchange. But I hope that it is possible to construct a continuing price feed of USD<->BTC purely within a p2p system itself. I think it should be possible if you implement something like localbitcoins within a p2p-blockchain using the idea of SSL logs to prove payment:
https://bitcointalksearch.org/topic/tlsnotary-cryptographic-proof-of-fiat-transfer-for-p2p-exchanges-173220So you would have a very slow p2p-trading system to convert between real USD and BTC by using bank wires. This would then generate the price feed for additional synthetic USD. Don't know if that makes sense, but I would be happy to hear some feedback on it...