Data outsourcing through cloud storage enables the users to share on-demand resources with cost effective IT services but several security issues arise like confidentiality, integrity and authentication. Each of them ...Data outsourcing through cloud storage enables the users to share on-demand resources with cost effective IT services but several security issues arise like confidentiality, integrity and authentication. Each of them plays an important role in the successful achievement of the other. In cloud computing data integrity assurance is one of the major challenges because the user has no control over the security mechanism to protect the data. Data integrity insures that data received are the same as data stored. It is a result of data security but data integrity refers to validity and accuracy of data rather than protect the data. Data security refers to protection of data against unauthorized access, modification or corruption and it is necessary to ensure data integrity. This paper proposed a new approach using Matrix Dialing Method in block level to enhance the performance of both data integrity and data security without using Third Party Auditor (TPA). In this approach, the data are partitioned into number of blocks and each block converted into a square matrix. Determinant factor of each matrix is generated dynamically to ensure data integrity. This model also implements a combination of AES algorithm and SHA-1 algorithm for digital signature generation. Data coloring on digital signature is applied to ensure data security with better performance. The performance analysis using cloud simulator shows that the proposed scheme is highly efficient and secure as it overcomes the limitations of previous approaches of data security using encryption and decryption algorithms and data integrity assurance using TPA due to server computation time and accuracy.展开更多
口令恢复是口令找回和电子取证的关键技术,而加密的Office文档被广泛使用,实现Office加密文档的有效恢复对信息安全具有重要的意义。口令恢复是计算密集型任务,需要硬件加速来实现恢复过程,传统的CPU和GPU受限于处理器结构,大大限制了...口令恢复是口令找回和电子取证的关键技术,而加密的Office文档被广泛使用,实现Office加密文档的有效恢复对信息安全具有重要的意义。口令恢复是计算密集型任务,需要硬件加速来实现恢复过程,传统的CPU和GPU受限于处理器结构,大大限制了口令验证速度的进一步提升。基于此,文中提出了基于FPGA集群的口令恢复系统。通过详细分析Office加密机制,给出了各版本Office的口令恢复流程。其次,在FPGA上以流水线结构优化了核心Hash算法,以LUT(Look Up Table)合并运算优化改进了AES(Advanced Encryption Standard)算法,以高速并行实现了口令生成算法。同时,以多算子并行设计了FPGA整体架构,实现了Office口令的快速恢复。最后,采用FPGA加速卡搭建集群,配合动态口令切分策略,充分发掘了FPGA低功耗高性能的计算特性。实验结果表明,无论在计算速度还是能效比上,优化后的FPGA加速卡都是GPU的2倍以上,具有明显的优势,非常适合大规模部署于云端,以缩短恢复时间找回口令。展开更多
文摘Data outsourcing through cloud storage enables the users to share on-demand resources with cost effective IT services but several security issues arise like confidentiality, integrity and authentication. Each of them plays an important role in the successful achievement of the other. In cloud computing data integrity assurance is one of the major challenges because the user has no control over the security mechanism to protect the data. Data integrity insures that data received are the same as data stored. It is a result of data security but data integrity refers to validity and accuracy of data rather than protect the data. Data security refers to protection of data against unauthorized access, modification or corruption and it is necessary to ensure data integrity. This paper proposed a new approach using Matrix Dialing Method in block level to enhance the performance of both data integrity and data security without using Third Party Auditor (TPA). In this approach, the data are partitioned into number of blocks and each block converted into a square matrix. Determinant factor of each matrix is generated dynamically to ensure data integrity. This model also implements a combination of AES algorithm and SHA-1 algorithm for digital signature generation. Data coloring on digital signature is applied to ensure data security with better performance. The performance analysis using cloud simulator shows that the proposed scheme is highly efficient and secure as it overcomes the limitations of previous approaches of data security using encryption and decryption algorithms and data integrity assurance using TPA due to server computation time and accuracy.
文摘口令恢复是口令找回和电子取证的关键技术,而加密的Office文档被广泛使用,实现Office加密文档的有效恢复对信息安全具有重要的意义。口令恢复是计算密集型任务,需要硬件加速来实现恢复过程,传统的CPU和GPU受限于处理器结构,大大限制了口令验证速度的进一步提升。基于此,文中提出了基于FPGA集群的口令恢复系统。通过详细分析Office加密机制,给出了各版本Office的口令恢复流程。其次,在FPGA上以流水线结构优化了核心Hash算法,以LUT(Look Up Table)合并运算优化改进了AES(Advanced Encryption Standard)算法,以高速并行实现了口令生成算法。同时,以多算子并行设计了FPGA整体架构,实现了Office口令的快速恢复。最后,采用FPGA加速卡搭建集群,配合动态口令切分策略,充分发掘了FPGA低功耗高性能的计算特性。实验结果表明,无论在计算速度还是能效比上,优化后的FPGA加速卡都是GPU的2倍以上,具有明显的优势,非常适合大规模部署于云端,以缩短恢复时间找回口令。
