Ad hoc networks are formed opportunistically as mobile
devices come within wireless communication range of each other.
Since individual devices are typically subject to severe resource
limitations, it is both possible and desirable for a device to
enhance its functionality by taking advantage (in a cooperative
manner) of capabilities available on other devices. Service
provision refers to the process by which devices advertise their
willingness to offer specific services and discover other
services. This paper describes a service provision model designed
specifically for use in ad hoc settings. Security policies
governing service accessibility can be specified at the
application level while secure communication among devices is
ensured by the implementation.