Focusing on the problem of encryption and querying of tenant private data on cloud database, a cloud database oriented Attribute Based Encryption (ABE) and query transform service middleware was proposed and realized. Firstly, the tenant symmetric keys were encrypted in the encryption and decryption component of the service middleware through attribute based encryption, and the ciphertext was generated and saved. Secondly, the query statements were translated in the query translation component so that they can be correctly executed on the encrypted database. Finally, the tenant privacy data was stored in the cloud database after symmetric encryption. The experimental results show that compared with the unencrypted database, the write time of the encrypted database is equivalent, while the querying time is increased by 10% to 150% according to the complexity of the query statement. The theoretical analysis shows that the proposed proxy decryption method is secure, and it has superiority over traditional Key Policy Attribute Based Encryption (KP-ABE) algorithm in time complexity.

Aiming at the problem that the traditional signal acquisition circuit needs a larger storage space to store data in the observation of radio astronomical signal, a hardware circuit design method for low frequency radio astronomical signal acquisition based on Modulated Wideband Converter (MWC) was proposed. Firstly, the observed signal was multiplied by four pseudo-random period signals, and then the results were divided into four channels. Secondly, the four-channel signals were filtered by second-order Butterworth low-pass filter repectively. Then, the four-channel filtered signals were sampled and the data were transferred to a Field-Programmable Gate Array (FPGA) for storage. Finally, the signal was reconstructed by Orthogonal Matching Pursuit (OMP) algorithm. The theoretical analysis and experimental results show that the Mean Square Error (MSE) between the reconstructed signal and the observed signal is 1.27×10 ^-2, and the compression rate of data storage space is 20%. The proposed hardware circuit design method reduces circuit design costs as well as storage space.

The Attribute Based Encryption (ABE) algorithm can support fine grained access control for cloud data. Concerning the problems that the ABE decryption has huge complexity and is difficult to realize on resource constrained mobile device, a mobile cloud storage-oriented attribute based decryption service middleware was proposed and realized. Without getting the information about the encrypted data, the middleware could delegate the ABE decryption service, a tree-based Linear Secret Sharing Scheme (LSSS) matrix solution was realized, and so the computation and communication cost of the mobile terminal were decreased. Accordingly, the decryption speed was improved. The attribute authority could revoke the user attributes through this middleware instantly with fine-grained control without involving any users. All the services were defined as Restful interface and then the generality of the middleware was ensured. The experimental results show that the middleware improves attribute based decryption performance nearly 30 times, and it has good parallel performance and practical attribute revoking capability.

In the cloud computing, the statistical multiplexing is a remarkable character, and the utilization efficiency of physical resource can be improved through the virtual technology. Aiming at the load balancing problem of the resource utilization needed to be discussed in the cloud virtual machine cluster, a Software Defined Network (SDN) based Anti-Saturated Grouping Strategy (ASGS) method was proposed according to the OpenStack cloud platform. The cloud hosts were separated into different groups based on their weights, and then the load information of cloud hosts were obtained by the SDN controller which used the probe with different groups periodically. When a request came, a group was selected randomly using the average weight of each group cloud hosts by the load balancer, and a proper backend was chosen by the polling method within the group. In order to avoid the cloud host downtime caused by the sudden increased requests for too many resources of a backend, the cloud host with higher weight was given a default parameter to increase the weight, and then the host would receive fewer requests on the higher load status. The experimental results show that, whatever the request number changes, the resource utilization standard variance of the proposed ASGS is always smaller than the random and round robin methods when time varies, which is nearly 0. The proposed ASGS has better load balance for the cloud host cluster.

Since the traditional centralized architecture Web service registry system suffers from such problems as performance bottleneck, single-point-of-failures, a structure Peer-to-Peer (P2P) based Web service registry system was designed and implemented. The registry system consists of six modules including configuration, schedule and distribution, peer-to-peer communication, rank validation, JUDDI, and network resources monitoring. The pastry based system scheduling and communication algorithms were proposed, and the corresponding Web service registration and discovery process was designed. The Web service registration system was tested and analyzed using SoapUI and LoadRunner. The experimental results show that the system can support large-scale accessing and has dynamic scalability. In the multi-concurrent simulation experiments, the response speeds of Web services registration and discovery are increased 1 times.

Because the functions of backup and recovery are usually ignored in the web anti-tamper system, a web anti-tamper system model is proposed in this paper, based on which a safe and efficient remote backup and recovery system is given. The multi-version management technical of backup data is used for restoring the data of different versions and different periods. The Lempel-Ziv-Markov chain Algorithm(LZMA) is used to compress the backup data for improving the disk utilization. The Data Encryption Standard(DES) and File Transfer Protocol(FTP) are used for securable remote date storage and transmission. Finally, the system performance test shows it can effectively backup and recover the WEB Server data without affecting the WEB Server load and recover a single page within 100ms. It’s an effective means to solve the web tampering problem.

In remote file synchronization of rsync algorithm, to resolve the shortage of large delta data between Server and Client, a new method of remote file synchronization was proposed. On the basis of rsync algorithm, the proposed method adopted delta compression technology, using block-move and KMP algorithm to find out the delta and match between Client and Server and using sliding window compression algorithm to compress the delta data. It is effective in reducing the delta data in network traffic. The experimental results show that delta can be reduced more than 97%, thus reducing network bandwidth consumption and increasing the efficiency of remote file synchronization.

An PCA-based location algorithm of human face features was presented.Eigenmouth was generated by prinicipal component analysis(PCA) with labelled mouth region image set.For an input image,the mouth region was recognized according to least residual error energy(LREE) criteria after the face region was first located.Then a restricted window scan stategy and comparability mearsurement P were introduced into the LREE algorithm.Experiment results show that the proposed method can locate mouth region easily,accurately and robustly.