In various embodiments, systems and methods for a trust architecture for telecommunication network slice security are disclosed. In some embodiments a trust architecture for telecommunication network slice security distributes network security functionality to individual network entities that constitute elements of a network slice instance. Slice network functions each individually implement components of the trust architecture for the network slice using a policy enforcement point (PEP) and a policy decision point (PDP). Each slice network function thus validates the authenticity and authorized privileges associated with the subject entity seeking a service from that slice network function, and grants or denies such service requests based on a policy implemented by the PEP and PDP.