Today, after the great development in the world of transportation and modern technologies (VANETs) is a network where several moving cars connecting with each other by an AD_HOC manner, the reason for that connection is to sharing useful statistics and information such as traffic situation, warning of collision, availability of parking and road quality. Extracting and analyzing then sharing this temporary facts will leads to collision avoidance, utilization of time, saving in fuel and enhance environment Securing this information is very important aspect in this day which noticed increment growth of cyber-attacks. for example if attackers illusion the road system with a flood of false data of roads situation after that guide all cars to the same road at that time the transposition sector of city will paralyzed. At other hand the securing of system should regard two facts, the first is the nature of information which is short-terms facts and continuously change. The second one is the vehicle microcomputer ability to encode transmit data and decode arrived information. Lightweight encryption algorithm offer a brilliant solution with tradeoff with the challenges that mention above. So the system in this thesis is suggested to use a (VANET) network with a modified encryption algorithm to be a Lightweight to protect information that will be shared between network parties.