Some of the difficulties that must be considered (and solved) in this regard are:
- Financial risk because of non-availability of funds, also because exposures may not be as visible or tools to take action if the system is exposed may not exist.
- Lost transactions and thus the need for reconciliation, with all the added complexities when dealing with many nodes.
- The challenges associated with the routing of clearing transactions between different systems (that work in different ways) and the need for different message-protocols or convergence.
- The contractual and commercial complexities in working with different parties with different needs and expectations.
- The implications of failed or disputed transactions (both in terms of business process and customer support)
I am sure all of these (and others that I can't think of right now) will be solved, but it will take baby steps first and dedication and hard work.