Proof of concept of a security based on lifetime of communication's pseudonyms for the VANETs

To make Vehicular Ad Hoc Network (VANET) applications useful to the users, the security problem must be solved. Recent researches have suggested the use of a set of anonymous keys certified by the issuing CA (Central authority) to preserve privacy, authentication, and confidentiality of the communicating entities. But how to determine the right time for the vehicles to exchange their communication pseudonyms and what would be the impacts on the network resources such as time processing and memory. In this paper, we propose a protocol that preserves authentication, non repudiation, and location privacy and helps vehicles to exchange their pseudonyms at roughly the same time. It is based on calculating the Euclidean distance and the average of the speed permitted on the path to evaluate the lifetime of the communication's pseudonyms. The exchange of the information is based on asymmetric and symmetric cryptography scheme and it uses hash function. The protocol permits to determine the expiration time of pseudonyms and how to make the distribution of all the road side units along the road in order to establish a good communication between them and the vehicles.