Double spending isn't really about trust. It's about transactional atomicity.
After reading a bit, I've concluded that Ripple doesn't actually solve the consensus problem. Whether it works or not depends on the shape of the graph of the core validating nodes. If the graph is too centralized (as it is now, and probably will always be), it can be controlled by fiat.
Transactional atomicity is exactly the reason why ripple needs a native currency - the native currency is what provides byzantine fault tolerance[1], just as in bitcoin.
Supposedly, ripple reaches consensus under diverse graphs of validator node networks. But its a research topic still undergoing study (Ripple Labs say they have whitehats closely examining the protocol).
Comments
Double spending isn't really about trust. It's about transactional atomicity.
After reading a bit, I've concluded that Ripple doesn't actually solve the consensus problem. Whether it works or not depends on the shape of the graph of the core validating nodes. If the graph is too centralized (as it is now, and probably will always be), it can be controlled by fiat.
Transactional atomicity is exactly the reason why ripple needs a native currency - the native currency is what provides byzantine fault tolerance[1], just as in bitcoin.
Supposedly, ripple reaches consensus under diverse graphs of validator node networks. But its a research topic still undergoing study (Ripple Labs say they have whitehats closely examining the protocol).
1. http://en.wikipedia.org/wiki/Byzantine_failure#Practical_Byz...