This work presents a contribution to secure the routing protocol GPSR (Greedy
Perimeter Stateless Routing) for vehicular ad hoc networks, we examine the
possible attacks against GPSR and security solutions proposed by different
research teams working on ad hoc network security. Then, we propose a solution
to secure GPSR packet by adding a digital signature based on symmetric
cryptography generated using the AES algorithm and the MD5 hash function more
suited to a mobile environment