Wi-Fi devices have limited battery life because of which conserving battery life is imperative. The 802.11 Wi-Fi standard provides power management feature that allows stations(STAs) to enter into sleep state to prese...Wi-Fi devices have limited battery life because of which conserving battery life is imperative. The 802.11 Wi-Fi standard provides power management feature that allows stations(STAs) to enter into sleep state to preserve energy without any frame losses. After the STA wakes up, it sends a null data or PS-Poll frame to retrieve frame(s) buffered by the access point(AP), if any during its sleep period. An attacker can launch a power save denial of service(PS-DoS) attack on the sleeping STA(s) by transmitting a spoofed null data or PS-Poll frame(s) to retrieve the buffered frame(s) of the sleeping STA(s) from the AP causing frame losses for the targeted STA(s). Current approaches to prevent or detect the PS-DoS attack require encryption,change in protocol or installation of proprietary hardware. These solutions suffer from expensive setup, maintenance, scalability and deployment issues. The PS-DoS attack does not differ in semantics or statistics under normal and attack circumstances.So signature and anomaly based intrusion detection system(IDS) are unfit to detect the PS-DoS attack. In this paper we propose a timed IDS based on real time discrete event system(RTDES) for detecting PS-DoS attack. The proposed DES based IDS overcomes the drawbacks of existing systems and detects the PS-DoS attack with high accuracy and detection rate. The correctness of the RTDES based IDS is proved by experimenting all possible attack scenarios.展开更多
A novel learning-based attack detection and estimation scheme is proposed for linear networked control systems(NCS),wherein the attacks on the communication network in the feedback loop are expected to increase networ...A novel learning-based attack detection and estimation scheme is proposed for linear networked control systems(NCS),wherein the attacks on the communication network in the feedback loop are expected to increase network induced delays and packet losses,thus changing the physical system dynamics.First,the network traffic flow is modeled as a linear system with uncertain state matrix and an optimal Q-learning based control scheme over finite-horizon is utilized to stabilize the flow.Next,an adaptive observer is proposed to generate the detection residual,which is subsequently used to determine the onset of an attack when it exceeds a predefined threshold,followed by an estimation scheme for the signal injected by the attacker.A stochastic linear system after incorporating network-induced random delays and packet losses is considered as the uncertain physical system dynamics.The attack detection scheme at the physical system uses the magnitude of the state vector to detect attacks both on the sensor and the actuator.The maximum tolerable delay that the physical system can tolerate due to networked induced delays and packet losses is also derived.Simulations have been performed to demonstrate the effectiveness of the proposed schemes.展开更多
针对恐怖袭击事件文本语料库匮乏的问题,文章制定了恐怖袭击事件的实体标注规范,通过对全球恐怖主义数据库(GTD)的数据进行实体标注,构建了恐怖袭击事件的实体语料库。同时,针对数据标注工作的高人力和高时间成本问题,由于百度通用信息...针对恐怖袭击事件文本语料库匮乏的问题,文章制定了恐怖袭击事件的实体标注规范,通过对全球恐怖主义数据库(GTD)的数据进行实体标注,构建了恐怖袭击事件的实体语料库。同时,针对数据标注工作的高人力和高时间成本问题,由于百度通用信息抽取(Universal Information Extraction,UIE)模型在极小样本上具有较强的泛化能力,采用UIE模型进行辅助标注。实验结果证明了标注方案的有效性,并在一定程度上减少了标注时间。展开更多
Software defined networking(SDN)has attracted significant attention from both academia and industry by its ability to reconfigure network devices with logically centralized applications.However,some critical security ...Software defined networking(SDN)has attracted significant attention from both academia and industry by its ability to reconfigure network devices with logically centralized applications.However,some critical security issues have also been introduced along with the benefits,which put an obstruction to the deployment of SDN.One root cause of these issues lies in the limited resources and capability of devices involved in the SDN architecture,especially the hardware switches lied in the data plane.In this paper,we analyze the vulnerability of SDN and present two kinds of SDN-targeted attacks:1)data-to-control plane saturation attack which exhausts resources of all SDN components,including control plane,data plane,and the in-between downlink channel and 2)control plane reflection attack which only attacks the data plane and gets conducted in a more efficient and hidden way.Finally,we propose the corresponding defense frameworks to mitigate such attacks.展开更多
Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global infor...Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global information source for every being. Despite all this, attacker knowledge by cybercriminals has advanced and resulted in different attack methodologies on the internet and its data stores. This paper will discuss the origin and significance of Denial of Service (DoS) and Distributed Denial of Service (DDoS). These kinds of attacks remain the most effective methods used by the bad guys to cause substantial damage in terms of operational, reputational, and financial damage to organizations globally. These kinds of attacks have hindered network performance and availability. The victim’s network is flooded with massive illegal traffic hence, denying genuine traffic from passing through for authorized users. The paper will explore detection mechanisms, and mitigation techniques for this network threat.展开更多
基金supported by TATA Consultancy Servies(TCS)Research Fellowship Program,India
文摘Wi-Fi devices have limited battery life because of which conserving battery life is imperative. The 802.11 Wi-Fi standard provides power management feature that allows stations(STAs) to enter into sleep state to preserve energy without any frame losses. After the STA wakes up, it sends a null data or PS-Poll frame to retrieve frame(s) buffered by the access point(AP), if any during its sleep period. An attacker can launch a power save denial of service(PS-DoS) attack on the sleeping STA(s) by transmitting a spoofed null data or PS-Poll frame(s) to retrieve the buffered frame(s) of the sleeping STA(s) from the AP causing frame losses for the targeted STA(s). Current approaches to prevent or detect the PS-DoS attack require encryption,change in protocol or installation of proprietary hardware. These solutions suffer from expensive setup, maintenance, scalability and deployment issues. The PS-DoS attack does not differ in semantics or statistics under normal and attack circumstances.So signature and anomaly based intrusion detection system(IDS) are unfit to detect the PS-DoS attack. In this paper we propose a timed IDS based on real time discrete event system(RTDES) for detecting PS-DoS attack. The proposed DES based IDS overcomes the drawbacks of existing systems and detects the PS-DoS attack with high accuracy and detection rate. The correctness of the RTDES based IDS is proved by experimenting all possible attack scenarios.
基金supported in part by the National Science Foundation(IIP 1134721,ECCS 1406533,CMMI 1547042)
文摘A novel learning-based attack detection and estimation scheme is proposed for linear networked control systems(NCS),wherein the attacks on the communication network in the feedback loop are expected to increase network induced delays and packet losses,thus changing the physical system dynamics.First,the network traffic flow is modeled as a linear system with uncertain state matrix and an optimal Q-learning based control scheme over finite-horizon is utilized to stabilize the flow.Next,an adaptive observer is proposed to generate the detection residual,which is subsequently used to determine the onset of an attack when it exceeds a predefined threshold,followed by an estimation scheme for the signal injected by the attacker.A stochastic linear system after incorporating network-induced random delays and packet losses is considered as the uncertain physical system dynamics.The attack detection scheme at the physical system uses the magnitude of the state vector to detect attacks both on the sensor and the actuator.The maximum tolerable delay that the physical system can tolerate due to networked induced delays and packet losses is also derived.Simulations have been performed to demonstrate the effectiveness of the proposed schemes.
文摘针对恐怖袭击事件文本语料库匮乏的问题,文章制定了恐怖袭击事件的实体标注规范,通过对全球恐怖主义数据库(GTD)的数据进行实体标注,构建了恐怖袭击事件的实体语料库。同时,针对数据标注工作的高人力和高时间成本问题,由于百度通用信息抽取(Universal Information Extraction,UIE)模型在极小样本上具有较强的泛化能力,采用UIE模型进行辅助标注。实验结果证明了标注方案的有效性,并在一定程度上减少了标注时间。
基金supported in part by the National Key R&D Program of China under Grant No.2017YFB0801701the National Science Foundation of China under Grant No.61472213CERNET Innovation Project(NGII20160123)
文摘Software defined networking(SDN)has attracted significant attention from both academia and industry by its ability to reconfigure network devices with logically centralized applications.However,some critical security issues have also been introduced along with the benefits,which put an obstruction to the deployment of SDN.One root cause of these issues lies in the limited resources and capability of devices involved in the SDN architecture,especially the hardware switches lied in the data plane.In this paper,we analyze the vulnerability of SDN and present two kinds of SDN-targeted attacks:1)data-to-control plane saturation attack which exhausts resources of all SDN components,including control plane,data plane,and the in-between downlink channel and 2)control plane reflection attack which only attacks the data plane and gets conducted in a more efficient and hidden way.Finally,we propose the corresponding defense frameworks to mitigate such attacks.
文摘Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global information source for every being. Despite all this, attacker knowledge by cybercriminals has advanced and resulted in different attack methodologies on the internet and its data stores. This paper will discuss the origin and significance of Denial of Service (DoS) and Distributed Denial of Service (DDoS). These kinds of attacks remain the most effective methods used by the bad guys to cause substantial damage in terms of operational, reputational, and financial damage to organizations globally. These kinds of attacks have hindered network performance and availability. The victim’s network is flooded with massive illegal traffic hence, denying genuine traffic from passing through for authorized users. The paper will explore detection mechanisms, and mitigation techniques for this network threat.
