  Content-Centric Networking (CCN) is an internetworking paradigm that offers
an alternative to today's IP-based Internet Architecture. Instead of focusing
on hosts and their locations, CCN emphasizes addressable named content. By
decoupling content from its location, CCN allows opportunistic in-network
content caching, thus enabling better network utilization, at least for
scalable content distribution. However, in order to be considered seriously,
CCN must support basic security services, including content authenticity,
integrity, confidentiality, authorization and access control. Current
approaches rely on content producers to perform authorization and access
control. This general approach has several disadvantages. First, consumer
privacy vis-a-vis producers is not preserved. Second, identity management and
access control impose high computational overhead on producers. Also,
unnecessary repeated authentication and access control decisions must be made
for each content request.
  These issues motivate our design of KRB-CCN - a complete authorization and
access control system for private CCNs. Inspired by Kerberos in IP-based
networks, KRB-CCN involves distinct authentication and authorization
authorities. By doing so, KRB-CCN obviates the need for producers to make
consumer authentication and access control decisions. KRB-CCN preserves
consumer privacy since producers are unaware of consumer identities. Producers
are also not required to keep any hard state and only need to perform two
symmetric key operations to guarantee that sensitive content is confidentially
delivered only to authenticated and authorized consumers. Most importantly,
unlike prior designs, KRB-CCN leaves the network (i.e., CCN routers) out of any
authorization, access control or confidentiality issues. We describe KRB-CCN
design and implementation, analyze its security, and report on its performance.
