  Future communication networks such as 5G are expected to support end-to-end
delivery of services for several vertical markets with diverging requirements.
Network slicing is a key construct that is used to provide end to end logical
virtual networks running on a common virtualised infrastructure, which are
mutually isolated. Having different network slices operating over the same 5G
infrastructure creates several challenges in security and trust. This paper
addresses the fundamental issue of trust of a network slice. It presents a
trust model and property-based trust attestation mechanisms which can be used
to evaluate the trust of the virtual network functions that compose the network
slice. The proposed model helps to determine the trust of the virtual network
functions as well as the properties that should be satisfied by the virtual
platforms (both at boot and run time) on which these network functions are
deployed for them to be trusted. We present a logic-based language that defines
simple rules for the specification of properties and the conditions under which
these properties are evaluated to be satisfied for trusted virtualised
platforms. The proposed trust model and mechanisms enable the service providers
to determine the trustworthiness of the network services as well as the users
to develop trustworthy applications. .
