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Structure and energy properties of carrier are considered as the most important factors to information hiding performance. This paper develops a new method to analyze energy and structure characteristics of digital images in order to preprocess the carriers. We adopt GHM multi-wavelet transformation to decompose the cover image into sub-images with different energy level. Then we obtain the embedding regions which are expressed as numerical range by discrete cosine transform. We embed data with different robustness in different regions. Then we get the stego image which is rarely changed in energy and structure properties compared with the original cover image. Experimental results indicate that the invisibility and robustness can be increased separately by 26.87% and 19.25% averagely, and the ability against steganalysis such as RS and Higher Order Statistics based on wavelet coefficients can be improved. Moreover, our algorithm has excellent sensitivity of image processing.

In the field of digital circuit design, the extensive applications of reusable intellectual property (IP) simplify the design procedure based on very large scale field programmable gate array (FPGA), and shorten the time to market (TTM). However, the flexibility of reusable IP makes itself easy to be stolen and illegally distributed by intruders. The protection method proposed in this paper maps IP owner's signature to combinational logic functions, and then implements these functions into unused lookup tables (LUTs) in the design based on FPGA, which can be used as a strong proof of IPs ownership. The related experiment results show that this protection method has favorable characteristics such as low overhead, few effects on performance, and high security.

Hardware designers tend to focus more on function correctness and performance parameters of the system than information security. As a result, hardware devices are disclosing confidential information through system side effects, which is vulnerable to attackers. Unfortunately, conventional security countermeasures such as encryption algorithms and access control mechanisms are inefficient in preventing information leakage through hard-to-detect covert channels. Recently, gate level information flow tracking (GLIFT) has been proposed to monitor all digital information flows in the underlying hardware and prevent information leakage caused by undesired interference between different hardware components. However, existing work in this realm restricts to combinational logic, which is not applicable for sequential circuits. This paper extends the GLIFT method to sequential logic and presents various methodologies for secure hardware design by enforcing bit-tight information flow control. Finally, experiments are conducted to evaluate area and performance overheads of the GLIFT method using sequential benchmarks.

Providing a safe computing condition to unknown user is a crucial task in the existing network computing, and usually we can use the sandbox technology to shield security issues, but the behavior of malicious-occupying the resource has not been well controlled in the sandbox. In this passage, permission rate to access the computational efficiency and accuracy can be available by improving the Linux Kernel Secure Computing Mode(Seccomp) System, furthermore using the system calls judgment technology to prevent its malicious acts from user code can protect the system. During the calculations procedure, specifically, the improved Perfect Bayesian Equilibrium (PBE) Algorithm can be used to determine user behavior in system-call process, utilize this algorithm to construct policy engine, and use the engine decision-making engine to decide existing users' behavior as a result to maximize the profits of both the user code operating and server system capacity. Moreover agent technology that works in achieving the interrupted determination and interrupted access separate the computing and operating systems simultaneously. After all, improving sandbox technology is to achieve the relative optimization between the user service efficiency and security guarantees. Finally, the experiments show that compared with the Sandboxie and Buffer Zone technology, the proposed algorithm optimizes the consumption of the system resources in the original Seccomp Sandbox, and its access determine in rate also speeds up in the certain degree. In particular, it can effectively prevent special system call from malicious code, which can protect the system mainly in large extent. Moreover, the testing speed and the performance of several regular system calls such as file access operation, write operation also are under the progressive improvement.

Position-based routing attracts more consideration in vehicular ad hoc networks (VANETs) for its efficiency and scalability. To enable the geographic forwarding a vehicle must be able to discover the position of the destination node typically depending on the location service. Considering the characteristics of city scenario, we proposed a scalable and effective location service called RSLS based on responsible sections (RS) which are intersections with traffic lights or bus stops. Vehicles only in RS act as location servers to store the latest position of vehicles and provide location query service. Using distributed hash-based RS selection algorithm a vehicle can easily determine its corresponding RSes. Simulations were done with realistic traffic pattern and the results show that RSLS achieves higher query success rate and better scalability than two well-known location services.

The performance of real-time video over wireless ad hoc networks is evaluated based on a novel real-time hardware in the loop test bed. The supporting capabilities of different ad hoc routing protocols and two common video coding algorithms are compared. Results show that the video packet delivery ratios of different routing protocols have similar trends of approximate linear descending with the increase of hop count after certain thresholds. The real-time video quality at more than 4-hop distance, where the packet delivery ratio is less than 75%, cannot be accepted. MPEG-2 can provide real-time video service within 3 hops, while the Motion JPEG cannot support multi-hop real-time video transport. The packet delivery ratio and the decoded block ratio, got with MPEG-2 has an average increase of 55.7% and 205.6%, compared with the results got with motion JPEG, respectively.

As an application of mobile ad hoc networks in transportation realm, Vehicular Ad hoc Network (VANET) is a prominent technology for inter-vehicle communications in Intelligent Transportation System. City environment is a main scenario for VANET applications, and routing for urban VANET faces greater challenges because of potential more uneven distribution of vehicular nodes, constrained mobility pattern and difficult signal reception due to radio obstacles. This paper investigates and compares several routing algorithms designed for urban VANET. A qualitative comparison of these approaches is provided as well as some opportunities for future research. The goals and key elements of a well-performed routing scheme are also proposed to help designing a solution to meet city scenarios.

AODV routing protocol is widely used in mobile ad hoc networks, but it does not have any security mechanism, so it is very vulnerable to security attacks. This paper analyses the common threats of AODV and then a security improvement is carried out. By setting up blackholes and rushing attack models, the performance of improved protocol is simulated using QualNet simulation tools. The results show that our security enhanced solution can not only protect against those attacks but also maintain the efficiency of AODV.