  We consider network graphs $G=(V,E)$ in which adjacent nodes share common
secrets. In this setting, certain techniques for perfect end-to-end security
(in the sense of confidentiality, authenticity (implying integrity) and
availability, i.e., CIA+) can be made applicable without end-to-end shared
secrets and without computational intractability assumptions. To this end, we
introduce and study the concept of a unique-neighborhood network, in which
nodes are uniquely identifiable upon their graph-topological neighborhood.
While the concept is motivated by authentication, it may enjoy wider
applicability as being a technology-agnostic (yet topology aware) form of
addressing nodes in a network.
