Proxy signature is widely used in large-scale wireless industrial control Internet of things, the efficiency of signature master server can be greatly improved by using proxy signature. A new short proxy signature scheme based on bilinear mapping was proposed to adapt to the application environment with limited bandwidth and weak computing power. Firstly, the security of the proposed scheme was proved based on Computational Diffie-Hellman (CDH) problem and Collusion Attack Algorithm with k traitors (k-CAA) problem under the random oracle model. Then, the performance advantages of the proposed scheme were analyzed with other existing proxy signature and short proxy signature schemes, and the key codes of the proposed scheme were given. The experimental results show that, the proposed scheme performs one scalar multiplication operation and one hash operation in proxy signature generation; two bilinear pairing operation, one scalar multiplication operation and two hash operations in signature verification. Compared with other similar proxy signature schemes, the proposed scheme has advantages in computational performance and is suitable for application scenarios with weak computational power and limited transmission capacity.

The analysis of aggregate proxy signature scheme proposed by Yu et al. (YU X Y, HE D K. A certificate-based aggregate proxy signature scheme. Journal of Central South University (Science and Technology), 2015, 46(12): 4535-4541.) showed that a valid signatures could be forged for any messages while knowing a valid signature. Therefore, an improved certificate-based aggregate proxy signature scheme was proposed and a new attack model was given. The new scheme was proved to be existentially unforgeable for the new attacker in random oracle model. The results show that the proposed scheme can resist conspiracy attacks and forgery attacks, and it is more suitable for the computation-constrained and real-time tasks.

Aiming at the research of the cooperative obstacle-avoidance tracing based on traditional flocking control model，which is proposed by Reynolds and implemented by Tanner, it has been improved by us and added the Steer to Avoid obstacle avoidance method. This model has a high efficiency in avoiding convex obstacle in tracking target. If the method is applied to the environment of concave obstacles, nodes will stuck in the concave zone and could not get out, because the target has an attraction power to nodes when it comes to a Steer to Avoid judgment. This paper proposed a new model for concave obstacles by further improving the Steer to Avoid method. Temporarily cancel the attraction from the target when it comes to a concave environment judgment, and then constantly searching the path along the edge of obstacles. Finally, nodes could get out of the concave obstacles and reach target. Simulation results showed that the proposed model，while compared to the traditional model, has a marked increase on average rate and time efficiency in avoiding obstacle. Also, it can succeed in avoiding mobile concave obstacles in unknown environment.

RPrime RSA private key operations was speeded up based on Chinese Remainder Theorem, and a bran-new authentication encryption scheme was proposed based on three-prime RPrime RSA and AES algorithm. Due to its high-efficiency and security, it is very suitable for the identification and exchange of information between smart cards, and between smart card and terminal.

Taking the Brownian dimension as their texture feature, image blocks were clustered and sorted, to control the number of domain blocks to be compared with each range block in coding. Furthermore, by combining techniques such as excluding plain blocks and building domain pool from averaged image, a fast algorithm for fractal coding was obtained, in which the coding time can be linearly controlled and predicted by the number of domain blocks compared with each range block. Experiment results indicate that with the same compression ratio, the proposed method improves the speed of coding with even better quality of decoded image, in contrast to existing classification and clustering methods.

The schemes to solve the high bit error problem in wireless networks were discussed. Aiming to improve the performance of TCP protocal in mobile environments, two typical TCP models of the pure end-to-end approaches, TCPW and TCP-Real,  were researched. The pure end-to-end schemes have the advantage of preserving the end-to-end semantics of TCP protocol. Simulation results with different bit error conditions of these protocols reveal an evident improvement in terms of TCP performance in relative to others, especially when the bit error rate is high.