Arguably the most important aspects for secure communication are entity authentication and authorization. Vehicles will have the capability of connecting with other entities through various mediums. Connections will require authentication methods in order to properly determine who is trying to communicate with system. In addition, authorization of those trying to communicate with the system must be verified. System integrity must be protected from malicious activity that can be propagated through the different mediums. This principle is similar to other computing platforms such as computers and mobile devices. However, V2I cases must be more restrictive due to the high assurance nature of the automotive industry. Unauthorized access to a vehicles system could allow for partial or complete control of vehicles to remote entities.

It is possible for attackers to set up makeshift road side units that fabricate messages to unsuspecting vehicles. The trouble with this security concern is its potential ease for attackers to set up trap sites using easily obtainable elements such as household routers. In addition, the algorithms and equipment used must be highly efficient and robust as attackers will gain considerable advantages in computing power and familiarity as the components age \cite{bin_key_2013}. Detecting and mitigating these types of attacks may require multi-level authentication measures and packet filtering techniques performed by dedicated security controllers \cite{hideaki_approaches_2013}.