Security-critical distributed systems have faced with malicious snooping and fault injection attack challenges. Traditional researches mainly focus on preventing malicious snooping which disregard fault injection attack threat. Concerning the above problem, the fault detection for message' encryption/decryption was considered, to maximize the fault coverage and minimize the heterogeneous degree of the messages' fault coverage. Firstly, Advanced Encryption Standard (AES) was used to protect confidentiality. Secondly, five fault detection schemes were proposed, and their fault coverage rates and time overheads were derived and measured, respectively. Finally, an efficient heuristic algorithm based on Simulated Annealing (SA) under the real-time constraint was proposed, which can maximize the fault coverage and minimize the heterogeneity. The experimental results show that the objective function value achieved by the proposed algorithm is 18% higher than that of the greedy algorithm at least, verifying the efficiency and robustness of the proposed algorithm.

The WCET (Worst Case Execution Time) is taken as the actual execution time of the task, which may cause a great waste of system resource. In order to solve the problem, a method based on stochastic task probability model was proposed. Firstly, Dynamic Voltage and Frequency Scaling (DVFS) was utilized to reduce the energy consumption by considering the effect of DVFS on the reliability of the system, the specific probability distribution of task execution time and the task requirement of No-Deadline Violation Probability (NDVP). Then, a new optimization algorithm with the operation time of polynomial was proposed based on the dynamic programming algorithm. In addition, the execution overhead of the algorithm was reduced by designing the state eliminating rules. The simulation results show that, compared with the optimal algorithm of the model of WCET, the proposed algorithm can reduce the system energy consumption by more than 30%. The experimental results indicate that considering the random execution time of tasks can save the system resources while ensuring the reliability of the system.

Focusing on the huge consumption of time and space and the absolute comparison result of Basic Block (BB) resulted from one-to-one mapping of basic block in traditional file structural similarity detection technique, a method based on dividing thought was proposed to accomplish structural comparison of binary file. Firstly, the small primes algorithm which is used to compare the basic block was improved to classify the basic blocks in a function, then the similar rates of basic blocks were obtained by combining with the weights of basic block signature and attribute, so as to get the final function similar rate and final file similar rate. In the comparison with the absolute comparison method which does not consider the partition at the similar rates of function, this proposed method has certain advantages in efficiency and accuracy. The experimental show that the proposed method improves the accuracy of comparison, and reduces the comparison time, it is more feasible in similarity comparison of binary files.

To prolong the lifetime in wireless sensor networks, the maximum lifetime routing based on ant colony algorithm (MLRAC) was proposed. This paper used the link energy consumption model and node transmission data probability to calculate the node total energy consumption in a data gathering cycle. Considering the node initial energy, MLRAC formulized the maximum lifetime routing into an optimal model. To solve the optimal model, the revised ant colony algorithm based on classical algorithm was proposed. It used new formulas for forwarding the probability of neighbor nodes and pheromone update, and a new method for packet detection. After some iterations of calculation, it could obtain the optimal network lifetime value and each node transmission data probability. Finally, sink node informed any other nodes in network with flooding. According to the received optimal probability, all nodes selected the neighbor node where the data packets did not pass to transmit data. The simulation results show that after a certain time of iteration, network lifetime of MLRAC reaches certain convergence. It can prolong network lifetime. Under certain conditions, MLRAC outperforms PEDAP-PA, LET, Sum-w and Ratio-w algorithms.

Patents and journals belong to different knowledge organization systems. To achieve the crossbrowsing and crossretrieval between journal literature and patents，the mapping problem between two classifications Chinese Library Classification (CLC) and International Patent Classification (IPC), must be addressed. According to the survey of the existing methods of classification mapping, this paper discussed a method to achieve the mapping between CLC and IPC based on machine learning. The learner was got by training the corpus identified by the CLC category, with which to classify the corpus identified by the IPC category. The mapping relations can be found after analyzing the classification results. And the comparison experiment proves the effectiveness of this method.

Simple power analysis is the most devastating attack on the security of elliptic curve scalar multiplication and can retrieve the secret key in some degree. A fast and secure side channel atomic elliptic curve scalar multiplication algorithm was put forward using the side channel atomic block S-A-N-A-M-N-A. In Jacobian coordination, the new algorithm used only 5M+5S+15A for doubling and 6M+6S+18A for mixed addition. In modified Jacobian coordination, the new algorithm used only 4M+4S+12A for doubling and 7M+7S+21A for mixed addition. Compared with the previous methods, the new method can improve the speed by about 7.8%~10% if S/M=0.8 or 18%~20% if S/M=0.6 for 192 bit scalar using NAF recoding.

The key pre-distribution based on LU composition of symmetric matrix is an effective approach to the Key management in the Wireless Sensor Networks (WSN). But there exists the possibility of failing to build the common communication key. To fix this defect and decrease communication traffic, a key pre-distribution scheme with authentication mechanism was proposed, which was based on the LU matrix scheme. Through optimizing the key pre-distribution scheme, we prove that the average communication traffic decreases by 16.7%. At last this scheme’s implementation in the Sun Spot Sensor and a detailed performance analysis were given out.