  This paper introduces CINNAMON, a software module that extends and seamlessly
integrates with the AUTOSAR "Secure Onboard Communication" (SecOC) module to
also account for confidentiality of data in transit. It stands for
Confidential, INtegral aNd Authentic on board coMunicatiON (CINNAMON). It takes
a resource-efficient and practical approach to ensure, at the same time,
confidentiality, integrity and authenticity of frames. The main new requirement
that CINNAMON puts forward is the use of encryption and thus, as a result,
CINNAMON exceeds SecOC against information gathering attacks. This paper sets
forth the essential requirements and specification of the new module by
detailing where and how to position it within AUTOSAR and by emphasizing the
relevant upgrades with respect to SecOC. The presentation continues with the
definition of a Security Profile and a summary of a prototype implementation of
ours. While CINNAMON is easily extensible, for example through the definition
of additional profiles, the current performances obtained on inexpensive boards
support the claim that the approach is feasible.
