Design And Implementation Of Covert Wideband Ad Hoc Network System Based On Acoustic Channel

As the issue of information security receives more and more attention,the traditional concept believes that disconnecting the connection between electronic devices and the Internet and cutting off the necessary conditions for the computer to be attacked,the security of the data can be ensured.Means for stealing and protecting private data on electronic devices are constantly developing in competition.For example,a hidden communication channel is established through high-frequency sound waves,which can communicate with isolated network devices with audio interfaces.With this kind of unconventional communication method,it is possible to open an Ad-Hoc network among different electronic devices,establish a network access and data communication mechanism for electronic devices that support simple audio interfaces,and exchange data in an isolated network environment.This process can not be perceived by the human.This paper mainly studies an Ad-Hoc network system that nodes communicate with each other based on high-frequency acoustic wave modulation and demodulation technology.Relying on the characteristics of acoustic wave transmission,high bandwidth,high concealment,and low equipment dependence,this paper design and realize a method that computers transport data by high-frequency acoustic wave in isolate network.The focus of this paper is to design a reliable transmission layer protocol and a medium access control protocol for acoustic connections,based on high-frequency sound waves(17.5k Hz?20.5k Hz)to achieve a continuous conversation and data transmission control scheme between network nodes.And apply this technology in the actual scenario.Main tasks of this paper are as follows:(1)Analyzed the sensitivity of the human ear to the frequency of sound waves and the frequency characteristics of common audio equipment.Determined the center frequency and bandwidth of the carrier used by the system,where the center frequency was 18 k Hz and the bandwidth was 3k Hz.(2)Researched and selected the structure of the system.Designed a cross-platform and highperformance application program.Designed the system functional graphicl interface,and selected the appropriate software-defined acoustic signal processing technology.(3)Designed schemes of node access and data transmission system through high-frequency acoustic network.Elaborated on the principle of transmission protocol,data frame structure design,avoidance mechanism of shared channel data conflict.Provided corresponding process analysis and implementation;(4)Design and realize the function of scanning,connection and file transmission between the computers in acoustic Ad Hoc network.And test the functions in the actual scene.(5)Test the performance under different types of equipment with different operating systems.Verify the concealment and adaptability of the system by ransmitting different types of data and files.This paper designd and implemented a communication networking system based on highfrequency acoustics.The human ear is not sensitive to high-frequency sound waves,which verified that electronic devices could perform complex data transmission tasks through highfrequency sound waves in isolation networks and relatively close-range scenarios.And test the system through specific experiments.