Single Secret Key Crptosystem for Secure and Efficient Exchange of Data in Cloud

Nowadays users are storing their personal data on a cloud storage because of its numerous advantages. One of the important advantage in cloud storage is sharing of data between users or between organizations. In this paper we propose a simple, flexible, efficient and secure data sharing method for the cloud users. Here we are describing a special type of public key encryption scheme where public key, master-secret key, single secret key and cipher text sizes are constant. Single secret key can be obtained by combining number of secret keys. The sender can securely share multiple files with receiver by encrypting each file using a separate public key. Then the sender will combine all the public keys to form a single secret key which is exchanged with receiver by using Diffie-Hellman algorithm. Advantage of small single secret key is user can store this decryption key on a resource constraint devices like smart cards, smart cell phones or sensor nodes. Receiver can download the number of files by using single secret key

A wide-area distributed cluster

中文摘要: 本文研究了广域网分布式集群的设计。与LVS 相比,这种集群的结构虽然复杂,但是能够克服传统集群的局限性,提供质量好,容量大,性价比高的解决方案。根据一种称之为CG 树的分布式集群的抽象模型,作者设计了自己CG 树算法。这种方案能有效的减少网络节点之间的通信开销,并能在集群系统出现故障时自动进行调整,保证了高可用性。模拟实验结果表明,该系统具有很好的性能。英文摘要：The paper studies the designs of wide-area distributed cluster. Although these kinds of cluster have more complex structure,they can overcome limitations of traditional cluster and provide resolutions with good quality, large capacity and high performance compared to LVS. Base on a model of distributed cluster, named CG tree, the author design his algorithms to manipulate CG trees. The scheme can efficiently reduce the cost of intercommunication between different networks, and can automatically adjust tree to ensure high availability when cluster faults occur. The result of simulated experiments indicates that the system has quite good performance.基金项目: 国家重点基础研究发展计划(973 计划) 项目(No.2007CB311005);国家863 计划项目(2006AA01Z129);福建省自然科学基金计划资助项目(A0710020);厦门大学985 二期信息创新平台项

KTR: An efficient key management scheme for secure data access control in wireless broadcast services recovery

Recent growth in brain-computer interface (BCI) research has increased pressure to report improved performance. However, different research groups report performance in different ways. Hence, it is essential that evaluation procedures are valid and reported in sufficient detail. In this chapter we give an overview of available performance measures such as classification accuracy, cohen’s kappa, information transfer rate (ITR), and written symbol rate. We show how to distinguish results from chance level using confidence intervals for accuracy or kappa. Furthermore, we point out common pitfalls when moving from offline to online analysis and provide a guide on how to conduct statistical tests on (BCI) results

Scalable Hierarchical Access Control in Secure Group Communications

Many group communications require a security infrastructure that ensures multiple levels of access privilege for group members. Access control in hierarchy is prevalent in multimedia applications, which consist of users that subscribe to different quality levels or different sets of data streams. In this paper, we present a multi-group key management scheme that achieves such a hierarchical access control by employing an integrated key graph and by managing group keys for all users with various access privileges. Compared with applying existing tree-based group key management schemes directly to the hierarchical access control problem, the proposed scheme significantly reduces the communication, computation and storage overhead associated with key management and achieves better scalability when the number of access levels increases. In addition, the proposed key graph is suitable for both centralized and contributory environments