The IEEE 1609.2 standard has been provided for application message security in WAVE (Wireless Access in Vehicular Environments)-based vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communications. This standard uses ECDSA signatures based on the NIST p256 curve for message authentication and integrity. In a complex urban traffic environment (for example, at an intersection in rush hour), the performance of signed message verification at OBUs on vehicles or RSUs on the road is a very important issue because a large number of automobiles can send messages while they are close to each other. In this paper, we design OpenCL based Implementation of ECDSA Signature Verification for V2X Communication and evaluate if this implementation improve the overall performance in OBU or RSU.