Biblio

In open network environments, since there is no centralized authority to monitor misbehaving entities, malicious entities can easily cause the degradation of the service quality. Trust has become an important factor to ensure network security, which can help entities to distinguish good partners from bad ones. In this paper, trust in open network environment is regarded as a self-organizing system, using self-organization principle of human social trust propagation, a genetic trust evaluation method with self-optimization and family attributes is proposed. In this method, factors of trust evaluation include time, IP, behavior feedback and intuitive trust. Data structure of access record table and trust record table are designed to store the relationship between ancestor nodes and descendant nodes. A genetic trust search algorithm is designed by simulating the biological evolution process. Based on trust information of the current node's ancestors, heuristics generate randomly chromosome populations, whose structure includes time, IP address, behavior feedback and intuitive trust. Then crossover and mutation strategy is used to make the population evolutionary searching. According to the genetic searching termination condition, the optimal trust chromosome in the population is selected, and trust value of the chromosome is computed, which is the node's genetic trust evaluation result. The simulation result shows that the genetic trust evaluation method is effective, and trust evaluation process of the current node can be regarded as the process of searching for optimal trust results from the ancestor nodes' information. With increasing of ancestor nodes' genetic trust information, the trust evaluation result from genetic algorithm searching is more accurate, which can effectively solve the joint fraud problem.

In the open network environment, the network offensive information is implanted in big data environment, so it is necessary to carry out accurate location marking of network offensive information, to realize network attack detection, and to implement the process of accurate location marking of network offensive information. Combined with big data analysis method, the location of network attack nodes is realized, but when network attacks cross in series, the performance of attack information tagging is not good. An accurate marking technique for network attack information is proposed based on big data fusion tracking recognition. The adaptive learning model combined with big data is used to mark and sample the network attack information, and the feature analysis model of attack information chain is designed by extracting the association rules. This paper classifies the data types of the network attack nodes, and improves the network attack detection ability by the task scheduling method of the network attack information nodes, and realizes the accurate marking of the network attacking information. Simulation results show that the proposed algorithm can effectively improve the accuracy of marking offensive information in open network environment, the efficiency of attack detection and the ability of intrusion prevention is improved, and it has good application value in the field of network security defense.

With the development of the interconnection of all things(IoT), a large number of mobile terminal devices with multiple users access the distribution network, and gradually form an open and interconnected network environment, which brings new challenges to the security and protection of the distribution network. In this paper, a method of analyzing the sensing data of the digital substation is proposed, which can prevent the abnormal data from causing the malfunction of the protective relays by calculating the creditability of the sensing data. Creditability calculation algorithm as well as the implementation of the intrusion tolerance strategy are studied throughout the paper. The simulation results show that the proposed creditability-based intrusion-tolerant(CIT) algorithm can ensure that the protective equipment have no protective malfunction from the false instructions or false data attacks, and the proposed intrusion tolerant algorithm has little affect on the real-time performance of the original protection algorithm, hence it has some practical value.

The transmission of medical image data in an open network environment is subject to privacy issues including patient privacy and data leakage. In the past, image encryption and information-hiding technology have been used to solve such security problems. But these methodologies, in general, suffered from difficulties in retrieving original images. We present in this paper an algorithm to protect key regions in medical images. First, coefficient of variation is used to locate the key regions, a.k.a. the lesion areas, of an image; other areas are then processed in blocks and analyzed for texture complexity. Next, our reversible data-hiding algorithm is used to embed the contents from the lesion areas into a high-texture area, and the Arnold transformation is performed to protect the original lesion information. In addition to this, we use the ciphertext of the basic information about the image and the decryption parameter to generate the Quick Response (QR) Code to replace the original key regions. Consequently, only authorized customers can obtain the encryption key to extract information from encrypted images. Experimental results show that our algorithm can not only restore the original image without information loss, but also safely transfer the medical image copyright and patient-sensitive information.

In the open network environment, the strange entities can establish the mutual trust through Automated Trust Negotiation (ATN) that is based on exchanging digital credentials. In traditional ATN, the attribute certificate required to either satisfied or not, and in the strategy, the importance of the certificate is same, it may cause some unnecessary negotiation failure. And in the actual situation, the properties is not just 0 or 1, it is likely to between 0 and 1, so the satisfaction degree is different, and the negotiation strategy need to be quantified. This paper analyzes the fuzzy negotiation process, in order to improve the trust establishment in high efficiency and accuracy further.