A broad range of information is being delivered to and used within modern vehicles. Information-based applications are becoming more highly integrated into the automobile. Security services are necessary to provide appropriate protection for this information. Encryption, digital signature, and hash functionalities enable information security services such as confidentiality, authentication, integrity and non-repudiation. However, the consumer of in-vehicle information services will not accept security services that introduce any inconvenience to their activities. This paper will discuss various security service methods and security management systems and propose methods to integrate these services acceptably into vehicle-based applications.