Thanks to the rapid development of vehicle-to-everything (V2X) and sensor technology, states of vehicles can be accurately measured and stored jointly in the cloud. These states can be viewed as a set of infinite attributes, such as the density around the motor vehicle, signal strength and so on. As such, the vehicle can be viewed as a moving object. The vehicle state can be measured, and its entropy is large. In vehicle networking, unicast communications between vehicles must be encrypted. The previous approach was to negotiate a session key through the Diffie-Hellman algorithm and then use the session key to encrypt the communications. This method not only needs to know in advance the peer IP of the communication, but it also needs a long time to establish a session key. Therefore, it is not suitable for vehicle networking. For the fast-changing vehicle networking, the session key establishment process should be shortened or even canceled. In this paper, we propose a method of Negotiation-free encryption for securing vehicular unicasting communications to improve the efficiency of vehicle ad hoc network transmissions.