基于LED显示屏的隐蔽光传输通道

Covert-Optical Transmission Channel based on LED Display

通过程序控制物理隔离计算机LED屏背光亮度,可以产生具有幅度调制特征的光泄漏信号,说明物理隔离计算机存在信息恶意泄漏的风险。因此,概述国内外隐蔽光传输通道的最新研究情况,设计了用于检测LED闪烁的光传感器,能够检测出基于脉冲宽度调制(PWM)的计算机LED显示屏的闪烁频率。通过控制亮度等级微弱变化,对计算机内信息进行光信号的幅度键控调制(ASK)发送,在人眼难以察觉的情况下,能够远距离接收还原泄露信息,从而实现了一种基于LED显示屏的新型隐蔽光传输通道。

By controlling the LED backlight brightness of the physically-isolated computer,a light leakage signal with amplitude modulation characteristics may be generated,and this means the physically-isolated computer has the risk of possible malicious information leakage.The latest research situation of covertoptical transmission channel at home and abroad is briefed.Meanwhile,the optical sensor for detecting LED flicker is designed,and this optical sensor can detect the flicker frequency of computer LED display based on PWM(Pulse Width Modulation).By controlling the slight changes of brightness level,the ASC(Amplitude Signal-Controlled)modulation transmission of the optical signal is done for the information in the computer,and the reduction leaked information can be received over a long distance in the case that the human eye is hard to perceive,thus realizing a novel cover-optical transmission channel based on LED display.