Biblio

With the rapid popularity of the network, the development of information encryption technology has a significant role and significance in securing network security. The security of information has become an issue of concern to the whole society, and the study of cryptography has been increasingly concerned, and the hash function is the core of modern cryptography, the most common hash algorithms are MD5 series of algorithms, SHA series of algorithms. MD5 is a popular and excellent typical Hash encryption technology today, which is used for password management, electronic signature, spam screening. In this paper, we focus on the improved MD5 algorithm with more efficiency, focusing on the internal structure of MD5, and finally making it more efficient in retrieval.

Having high safety and effective computational property, the elliptic curve cryptosystem is very suitable for embedded mobile environment with resource constraints. Power attack is a powerful cipher attack method, it uses leaking information of cipher-chip in its operation process to attack chip cryptographic algorithms. In view of the situation that the power attack on the elliptic curve cryptosystem mainly concentrates on scalar multiplication operation an improved algorithm FWNAF based on RWNAF is proposed. This algorithm utilizes the fragments window technology further improves the utilization ratio of the storage resource and reduces the “jitter phenomenon” in system computing performance caused by the sharp change in system resources.

Data secure deletion operation in storage media is an important function of data security management. The internal physical properties of SSDs are different from hard disks, and data secure deletion of disks can not apply to SSDs directly. Copyback operation is used to improve the data migration performance of SSDs but is rarely used due to error accumulation issue. We propose a data securely deletion algorithm based on copyback operation, which improves the efficiency of data secure deletion without affecting the reliability of data. First, this paper proves that the data secure delete operation takes a long time on the channel bus, increasing the I/O overhead, and reducing the performance of the SSDs. Secondly, this paper designs an efficient data deletion algorithm, which can process read requests quickly. The experimental results show that the proposed algorithm can reduce the response time of read requests by 21% and the response time of delete requests by 18.7% over the existing algorithm.

With the gradual construction and implementation of cloud computing, the information security problem of the smart grid has surfaced. Therefore, in the construction of the smart grid cloud computing platform, information security needs to be considered in planning, infrastructure, and management at the same time, and it is imminent to build an information network that is secure from terminal to the platform to data. This paper introduces the concept of cloud security technology and the latest development of cloud security technology and discusses the main strategies of cloud security construction in electric power enterprises.

In a group shilling attack, attackers work collaboratively to inject fake profiles aiming to obtain desired recommendation result. This type of attacks is more harmful to recommender systems than individual shilling attacks. Previous studies pay much attention to detect individual attackers, and little work has been done on the detection of shilling groups. In this work, we introduce a topic modeling method of natural language processing into shilling attack detection and propose a shilling group detection method on the basis of hierarchical topic model. First, we model the given dataset to a series of user rating documents and use the hierarchical topic model to learn the specific topic distributions of each user from these rating documents to describe user rating behaviors. Second, we divide candidate groups based on rating value and rating time which are not involved in the hierarchical topic model. Lastly, we calculate group suspicious degrees in accordance with several indicators calculated through the analysis of user rating distributions, and use the k-means clustering algorithm to distinguish shilling groups. The experimental results on the Netflix and Amazon datasets show that the proposed approach performs better than baseline methods.

Aiming at group shilling attacks in recommender systems, a shilling group detection approach based on triangle dense subgraph mining is proposed. First, the user relation graph is built by mining the relations among users in the rating dataset. Second, the improved triangle dense subgraph mining method and the personalizing PageRank seed expansion algorithm are used to divide candidate shilling groups. Finally, the suspicious degrees of candidate groups are calculated using several group detection indicators and the attack groups are obtained. Experiments indicate that our method has better detection performance on the Amazon and Yelp datasets than the baselines.

In view of the continuous progress of current science and technology, cloud computing has been widely used in various fields. This paper proposes a secure data storage architecture based on cloud computing. The architecture studies the security issues of cloud computing from two aspects: data storage and data security, and proposes a data storage mode based on Cache and a data security mode based on third-party authentication, thereby improving the availability of data, from data storage to transmission. Corresponding protection measures have been established to realize effective protection of cloud data.

Vehicle Ad-hoc Networks (VANETs) have recently become an active research area. This is because of its important applications in the transportation field in which vehicles have severe position during activities of daily living in persons. In this paper, the basic background of the VANET from the Intelligent Transportation System (ITS), Mobile Ad-hoc Networks (MANETs), VANET standard and VANET characteristics are discussed. Second, the architecture from components and communications of the system are presented. Then, the critical challenges and future perspectives in this field are comprehensively reviewed. This paper could serve as a guide and reference in the design and development of any new techniques for VANETs. Moreover, this paper may help researchers and developers in the selection of the main features of VANET for their goals in one single document.

The current network security situation of the electric power dispatching and control system is becoming more and more severe. On the basis of the original network security management platform, to increase the collection of network security data information and improve the network security analysis ability, this article proposes the electric power dispatching and control system network security situation awareness analysis module. The perception layer accesses multi-source heterogeneous data sources. Upwards through the top layer, data standardization will be introduced, who realizes data support for security situation analysis, and forms an association mapping with situation awareness elements such as health situation, attack situation, behavior situation, and operation situation. The overall effect is achieving the construction goals of "full control of equipment status, source of security attacks can be traced, operational risks are identifiable, and abnormal behaviors can be found.".

The Moving Picture Experts Group's Compact Descriptors for Visual Search (MPEG's CDVS) intends to standardize technologies in order to enable an interoperable, efficient, and cross-platform solution for internet-scale visual search applications and services. Among the key technologies within CDVS, we recall the format of visual descriptors, the descriptor extraction process, and the algorithms for indexing and matching. Unfortunately, these steps require precision and computation accuracy. Moreover, they are very time-consuming, as they need running times in the order of seconds when implemented on the central processing unit (CPU) of modern mobile devices. In this paper, to reduce computation times and maintain precision and accuracy, we re-design, for many-cores embedded graphical processor units (GPUs), all main local descriptor extraction pipeline phases of the MPEG's CDVS standard. To reach this goal, we introduce new techniques to adapt the standard algorithm to parallel processing. Furthermore, to reduce memory accesses and efficiently distribute the kernel workload, we use new approaches to store and retrieve CDVS information on proper GPU data structures. We present a complete experimental analysis on a large and standard test set. Our experiments show that our GPU-based approach is remarkably faster than the CPU-based reference implementation of the standard, and it maintains a comparable precision in terms of true and false positive rates.