Call drop is one of the most common problems encountered by ISP with PSTN access. In this pacer several reasons on server side that cause modem disconnection are analyzed. In the last part of this paper, some solution...Call drop is one of the most common problems encountered by ISP with PSTN access. In this pacer several reasons on server side that cause modem disconnection are analyzed. In the last part of this paper, some solutions are Put forward to reduce call drop rate.展开更多
With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To addres...With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To address these challenges, the server-aided access control(SAAC) system was proposed. The SAAC system builds upon a variant of conditional proxy re-encryption(CPRE) named threshold conditional proxy re-encryption(TCPRE). In TCPRE, t out of n proxies can re-encrypt ciphertexts(satisfying some specified conditions) for the delegator(while up to t-1 proxies cannot), and the correctness of the re-encrypted ciphertexts can be publicly verified. Both features guarantee the trust and reliability on the proxies deployed in the SAAC system. The security models for TCPRE were formalized, several TCPRE constructions were proposed and that our final scheme was secure against chosen-ciphertext attacks was proved.展开更多
文摘Call drop is one of the most common problems encountered by ISP with PSTN access. In this pacer several reasons on server side that cause modem disconnection are analyzed. In the last part of this paper, some solutions are Put forward to reduce call drop rate.
基金The National Natural Science Foundation of China(No.61272413,No.61472165)
文摘With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To address these challenges, the server-aided access control(SAAC) system was proposed. The SAAC system builds upon a variant of conditional proxy re-encryption(CPRE) named threshold conditional proxy re-encryption(TCPRE). In TCPRE, t out of n proxies can re-encrypt ciphertexts(satisfying some specified conditions) for the delegator(while up to t-1 proxies cannot), and the correctness of the re-encrypted ciphertexts can be publicly verified. Both features guarantee the trust and reliability on the proxies deployed in the SAAC system. The security models for TCPRE were formalized, several TCPRE constructions were proposed and that our final scheme was secure against chosen-ciphertext attacks was proved.
文摘针对某煤矿机械制造企业数据库系统用户数量较多而影响数据库系统安全性能的问题,提出了一种基于SQL Server的数据库系统安全机制的设计方案;详细介绍了该安全机制中登录身份模式选择、应用程序验证、创建SQL Server组、设置数据库访问、设置与分配用户权限以及其他安全机制的设计;指出在设计该安全机制时,应首先创建全局组,通过SQL Server Users组获得服务器访问,通过具体数据库组获得数据库访问权限,然后根据用户访问需求创建数据库角色并对角色分配权限,最后全局组通过加入角色获得权限,从而可确保数据库系统的安全。实际应用验证了该安全机制的可行性和有效性。
