A protocol that could be used in the hardware token case can also be used to solve this case. There are at least two possible solutions for providing software credential mobility.
Availability is also at a premium.
A credential server must be reachable from many different types of client with different characteristics in terms of processing power, storage and network connectivity. The purpose of this working group is therefore to gather requirements for a solution or set of solutions beneficial to the Internet community, establish a framework for such a solution, and to develop, adapt, or adopt the required protocols and credential formats.