The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-inpu...The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.展开更多
Security of information system requires a secure operation system. Security kernel meets the requirement and provides a bedrock to security of operation system. This paper extracts the deficiency of traditional securi...Security of information system requires a secure operation system. Security kernel meets the requirement and provides a bedrock to security of operation system. This paper extracts the deficiency of traditional security kernel, presents a security kernel mechanism supporting policy flexibility, simplified secure interface. It optimizes the performance by reused policy cache, provids a method to revoke granted permissions and assures the atomicity of revocation permissions and granting new permissions. As a result, all refinements help security kernel to improve its flexibility, extensibility and portability.展开更多
文摘近日,武汉大学国家网络安全学院2023级硕士研究生闫楠作为第一作者撰写的论文被第34届USENIX安全研讨会(The34th USENIX Security Symposium 2025)录用。论文题目为“Embed X:Embedding-Based Cross-Trigger Backdoor Attack Against Large Language Models”(《Embed X:基于嵌入的跨触发器大语言模型后门攻击》),指导老师为国家网络安全学院副研究员李雨晴(通信作者)、教授陈晶(通信作者)、副教授何琨。华中科技大学副教授王雄、香港科技大学教授李波参与合作。
文摘The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.
文摘Security of information system requires a secure operation system. Security kernel meets the requirement and provides a bedrock to security of operation system. This paper extracts the deficiency of traditional security kernel, presents a security kernel mechanism supporting policy flexibility, simplified secure interface. It optimizes the performance by reused policy cache, provids a method to revoke granted permissions and assures the atomicity of revocation permissions and granting new permissions. As a result, all refinements help security kernel to improve its flexibility, extensibility and portability.
