隐蔽通道利用了网络协议的特点来秘密进行数据的传输,严重威胁信息安全.大多数ICMP流量可以躲避防火墙等网络设备的检测,因此,攻击者利用网际控制报文协议(Internet control message protocol,ICMP)将数据隐藏在ICMP的有效负载部分,形成...隐蔽通道利用了网络协议的特点来秘密进行数据的传输,严重威胁信息安全.大多数ICMP流量可以躲避防火墙等网络设备的检测,因此,攻击者利用网际控制报文协议(Internet control message protocol,ICMP)将数据隐藏在ICMP的有效负载部分,形成ICMP隐蔽通道.传统ICMP通道检测基于有效负载单一特征,为了更有效进行检测,通过分析ICMP协议,对正常ICMP流量的类型、数据包大小、数据固定格式等基本数据特征信息进行充分讨论,并用现有的一些ICMP隐蔽信息工具构建隐蔽通道,基于ICMP协议信息的12个特征,提出了基于支持向量机(support vector machine,SVM)的ICMP隐蔽信道检测算法.该算法通过提取网络流特征字段,采用SVM训练模型,检测结果表明,能较准确检测到ICMP隐蔽流量,且检测率较高,达到99%左右.展开更多
There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks (MANET). In this paper...There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks (MANET). In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol (ICMP) based ping and transmission control protocol (TCP) based streaming video applications using optimised link state routing (OLSR) implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.展开更多
With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or ...With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or a server, by degrading its computing performance or by preventing legitimate users from accessing its services. Recently, Operating Systems (OS) are increasingly deploying embedded DDoS prevention schemes to prevent computing exhaustion caused by such attacks. In this paper, we compare the effectiveness of two popular operating systems, namely the Apple’s Lion and Microsoft’s Windows 7, against DDoS attacks. We compare the computing performance of these operating systems under two ICMP based DDoS attacks. Since the role of the OS is to manage the computer or servers resources as efficiently as possible, in this paper we investigate which OS manages its computing resources more efficiently. In this paper, we evaluate and compare the built-in security of these two operating systems by using an iMac computer which is capable of running both Windows 7 and Lion. The DDoS attacks that are simulated for this paper are the ICMP Ping and Land Attack. For this experiment, we measure the exhaustion of the processors and the number of Echo Request and Echo Reply messages that were generated under varying attack loads for both the Ping and Land Attack. From our experiments, we found that both operating systems were able to survive the attacks however they reacted a bit differently under attack. The Operating System Lion was handling both the Ping and Land attack in the exactly the same way, whereas Windows 7 handled the two attacks a bit differently, resulting in different processor consumptions by two different operating systems.展开更多
文摘There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks (MANET). In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol (ICMP) based ping and transmission control protocol (TCP) based streaming video applications using optimised link state routing (OLSR) implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.
文摘With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or a server, by degrading its computing performance or by preventing legitimate users from accessing its services. Recently, Operating Systems (OS) are increasingly deploying embedded DDoS prevention schemes to prevent computing exhaustion caused by such attacks. In this paper, we compare the effectiveness of two popular operating systems, namely the Apple’s Lion and Microsoft’s Windows 7, against DDoS attacks. We compare the computing performance of these operating systems under two ICMP based DDoS attacks. Since the role of the OS is to manage the computer or servers resources as efficiently as possible, in this paper we investigate which OS manages its computing resources more efficiently. In this paper, we evaluate and compare the built-in security of these two operating systems by using an iMac computer which is capable of running both Windows 7 and Lion. The DDoS attacks that are simulated for this paper are the ICMP Ping and Land Attack. For this experiment, we measure the exhaustion of the processors and the number of Echo Request and Echo Reply messages that were generated under varying attack loads for both the Ping and Land Attack. From our experiments, we found that both operating systems were able to survive the attacks however they reacted a bit differently under attack. The Operating System Lion was handling both the Ping and Land attack in the exactly the same way, whereas Windows 7 handled the two attacks a bit differently, resulting in different processor consumptions by two different operating systems.