基于OpenVPN识别的APT隐蔽隧道检测

随着因特网与信息安全的发展,出现了一种新的攻击方式:高级持续性威胁(APT)。在APT的最后阶段,当攻击者想要从受害网络中窃取数据时,他们可能会使用隐蔽隧道。虚拟专用网络是私人或公共网络间的点对点连接。在过去几年里,VPN一直被认为是安全的。事实上,它也可以带来很多潜在的安全隐患。例如,攻击者可以利用虚拟专用网,使其称为一个用来传输敏感数据的APT隐蔽隧道。鉴于这样的双刃剑,有必要找到一种方法来检测恶意虚拟专用网,以防止APT隐蔽隧道的存在。

On Generality of the Data Plane and Scalability of the Control Plane in Software-Defined Networking

The control and data planes are decoupled in software-defined networking(SDN),which enables both planes to evolve independently,and brings about many advantages such as high flexibility,programmability,and rapid implementation of new network protocols.However,in order to improve the scalability of the control plane at present,some control functionalities are added to the data plane,which is probably to impact on the generality of the data plane.The key challenge of adding control functionalities to the data plane is to strike a careful balance between the generality of the data plane and the scalability of the control plane.We propose some basic principles that both control and data planes should comply with,based on the evolutionary trend of SDN.Moreover,we take two approaches for reference according to the principles,viewed from the control messages in OpenFlow-based SDN.Our evaluations demonstrate that the approaches can maintain the generality of the data plane and improve the scalability of the control plane.

WiFi over Fiber Link and Wavelength Assignment Protocol for Internet of Things

A novel Wireless Fidelity (WiFi) over fiber link and a wavelength assignment protocol are proposed to provide sufficient bandwidth and extensive coverage range for the various applications in the Internet of Things (IoT).The performance of the WiFi over fiber-based wireless IoT network is evaluated in terms of error vector magnitude (EVM) and data throughput for both the up and down links between the WiFi central control system and remote radio units (RRUs).The experimental results illustrate the reliability of the fiber transmission of 64 Quadrature Amplitude Modulation (64QAM) WiFi signals by direct analog modulation.In order to efficiently utilize the wavelength resources,we also demonstrated the wavelength assignment protocol by employing optical switching configurations in Central Station (CS) to realize the wavelength switching,and the simulation results indicate the queuing size and the corresponding queue delay for different numbers of available wavelengths.

Analysis of Fast and Secure Protocol Based on Continuous-Time Markov Chain

To provide an optimal alternative to traditional Transmission Control Protocol(TCP)-based transport technologies,Aspera's Fast and Secure Protocol(FASP)is proposed as an innovative bulky data transport technology.To accurately analyse the reliability and rapidness of FASP,an automated formal technique - probabilistic model checking - is used for formally analysing FASP in this paper.First,FASP's transmission process is decomposed into three modules:the Sender,the Receiver and the transmission Channel.Each module is then modelled as a Continuous-Time Markov Chain(CTMC).Second,the reward structure for CTMC is introduced so that the reliability and rapidness can be specified with the Continuous-time Stochastic Logic(CSL).Finally,the probabilistic model checker,PRISM is used for analysing the impact of different parameters on the reliability and rapidness of FASP.The probability that the Sender finishes sending data and the Receiver successfully receives data is always 1,which indicates that FASP can transport data reliably.The result that FASP takes approximately 10 s to complete transferring the file of 1 G irrespective of the network configuration shows that FASP can transport data very quickly.Further,by the comparison of throughput between FASP and TCP under various latency and packet loss conditions,FASP's throughput is shown to be perfectly independent of network delays and robust to extreme packet loss.

Design and implementation of the optical fiber control and transmission module in multi-channel broadband digital receiver

An optical fiber control and transmission module is designed and realized based on Virtex-7 field programmable gata array(FPGA), which can be applied in multi-channel broadband digital receivers. The module consists of sampling data transfer submodule and multi-channel synchronous sampling control submodule. The sampling data transmission in 4× fiber link channel is realized with the self-defined transfer protocol. The measured maximum data rate is 4.97 Gbyte/s. By connecting coherent clocks to the transmitter and receiver endpoints and using the self-defined transfer protocol, multi-channel sampling control signals transferred in optical fibers can be received synchronously by each analog-to-digital converter(ADC) with high accuracy and strong anti-interference ability. The module designed in this paper has certain reference value in increasing the transmission bandwidth and the synchronous sampling accuracy of multi-channel broadband digital receivers.

Research on Fiber-grating-based Wireless Sensor Networks

A 20-node fiber-grating-based wireless sensor network is proposed and experimentally demonstrated. Each sensor node is integrated with the light source, 1-3 FBG sensing probes, wavelength demodulation, and wireless communication module. Via self-organized clusters and low energy adaptive clustering hierarchy （LEACH） route protocols, the sensor nodes are able to exchange sensing data with the control center, and the maximum communication radius of a sensor node is over 170m. The sensor node is battery-powered with a survival lifetime of up to 120 days at a network refresh rate of 5 minutes.