  Several years of academic and industrial research efforts have converged to a
common understanding on fundamental security building blocks for the upcoming
Vehicular Communication (VC) systems. There is a growing consensus towards
deploying a Vehicular Public-Key Infrastructure (VPKI) enables pseudonymous
authentication, with standardization efforts in that direction. However, there
are still significant technical issues that remain unresolved. Existing
proposals for instantiating the VPKI either need additional detailed
specifications or enhanced security and privacy features. Equally important,
there is limited experimental work that establishes the VPKI efficiency and
scalability. In this paper, we are concerned with exactly these issues. We
leverage the common VPKI approach and contribute an enhanced system with
precisely defined, novel features that improve its resilience and the user
privacy protection. In particular, we depart from the common assumption that
the VPKI entities are fully trusted and we improve user privacy in the face of
an honest-but-curious security infrastructure. Moreover, we fully implement our
VPKI, in a standard-compliant manner, and we perform an extensive evaluation.
Along with stronger protection and richer functionality, our system achieves
very significant performance improvement over prior systems - contributing the
most advanced VPKI towards deployment.
