To avoid the failure of data forwarding, brought by some characteristics of Vehicular Ad Hoc Networks (VANET), uniform distribution of vehicles, frequent network partition and mergence, etc., a new data delivery method based on Weak State Routing (WSR) from Traffic Control Center (TCC) to driving vehicles, called Weak State Forwarding (WSFD), was introduced in VANET. Firstly, a data packet collected by TCC was delivered to an Access Point (AP) along the direction of the destination vehicle. Secondly, the data packet was forwarded to the destination vehicle by AP within its communication range, at the same time, the location information of destination vehicle was carried by the data packet. Then, after comparing all the mapping information owned by the vehicle which received the data packet, the most deterministic map information was chosen by the vehicle and compared to the location information carried by the data packet so as to ensure the next forwarding direction. If the confidential level was quite high, the data packet was revised to move towards the mapping's corresponding central area, meanwhile, the information of destination vehicle carried by the data packet was updated. Otherwise, the original direction would be kept. Lastly, through several times' forwarding and revising, the data packet would be gradually approached to the area where the destination vehicle located, and the whole data delivery would be finally completed. Compared with Trajectory-based Statistical Forwarding for multihop infrastructure-to-vehicle data delivery (TSF) and Greedy Perimeter Stateless Routing (GPSR) algorithm, the WSFD algorithm could reduce the delivery delay to 5 seconds or less and elevate the delivery rate to 0.92 or more generally in the experiment of data transmission in 30 km*30 km square area. The experimental results show that the WSFD algorithm can improve safety of drivers and alleviate the traffic jam effectively.

In extreme weather or traffic, passengers cannot get a taxi to the destination quickly, thus a taxi unified recommendation algorithm based on region partition was proposed to provide common taxi service and carpooling service. First of all, the region was regarded as the logo of journey, making the journey matching possible. Secondly, in the carpooling service, the similar routes of two passengers were matched in real-time to help passenger carpool sharing. Finally, the taxi with the minimum percentage of bypass time was selected to recommend to the user. The Global Positioning System (GPS) data of 14747 taxis was used to evaluate the proposed algorithm. Compared with CallCab system, the total mileage of the proposed algorithm was dropped by about 10%, while the carpooling time was only raised by 6% on average, as well as the total passenger mileage was reduced by 30%. Experimental results show that the proposed algorithm not only can significantly reduce the emission of automotive exhaust, but also has better performance in terms of time consumption.

To solve the attributes authority and attributes revocation of Attribute-Based Encryption (ABE) in Wireless Sensor Network (WSN), a scheme of trust management-based ciphertext-policy ABE (TM-CP-ABE) was proposed. The proposed scheme was based on ciphertext-policy ABE and combined it with trust management mechanism. The procedure and the steps of trust evaluation based attributes authority and trust update based attributes revocation were provided. The security, complexity and validity of the proposed scheme were analyzed. Compared with the popular encryption scheme in WSN through comprehensive simulation, the results show that the proposed scheme is efficient for attribute revocation of CP-ABE in WSN. By attributes revocation, to a certain extent, the attacks of malicious nodes are also inhibited.

There is a potential security risk in the communication process by using QR (Quick Response) code. This paper, therefore, proposed an encryption algorithm. Ising model has a matrix form, in which it is same with QR code, and its process of state change supports parallel operation. An encryption matrix was generated according to the model’s change rule, and then the ciphertext of QR code was produced, using the matrix and combining coding theory of the code. It was proven by the experiments that the algorithm did well in terms of randomness and sensitivity of key. With its simplicity, security and high efficiency, it could be applied to the secure communication for QR code.