AIRCODE: Hidden Screen-Camera Communication on an Invisible and Inaudible Dual Channel


Kun Qian, Tsinghua University and University of California San Diego; Yumeng Lu, Zheng Yang, Kai Zhang, Kehong Huang, and Xinjun Cai, Tsinghua University; Chenshu Wu, University of Maryland College Park; Yunhao Liu, Tsinghua University and Michigan State University


Hidden screen-camera communication emerges as a key enabler for the next generation videos that allow side information, such as TV commercials, augmented contents, and even the video itself, to be delivered to machines during normal watching. To guarantee imperceptibility to human eyes, existing solutions have to sacrifice data rate and reliability enormously. This paper presents AIRCODE, a hidden screen-camera communication system built upon invisible visual and inaudible audio dual channel. While ensuring great unobtrusiveness, AIRCODE achieves robust communication at a remarkably high rate of 1Mbps, for the first time, enabling imperceptible transmission of not only texts but also videos. AIRCODE makes two key technical contributions. First, AIRCODE takes the complementary advantages of video and audio channels by exploiting the reliable yet low-rate inaudible audio link as the control channel while the unreliable but high-rate visual link as the data channel. Second, AIRCODE incorporates visual odometry to accurately identify and track the captured screen, regardless of dynamic video contents and surrounding interference. Experiments on commercial monitors and smartphones demonstrate that AIRCODE significantly outperforms the state-of-the-art system, yielding a remarkable data rate of 1069 Kbps while with BER of 5%.

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@inproceedings {262007,
author = {Kun Qian and Yumeng Lu and Zheng Yang and Kai Zhang and Kehong Huang and Xinjun Cai and Chenshu Wu and Yunhao Liu},
title = {{AIRCODE}: Hidden {Screen-Camera} Communication on an Invisible and Inaudible Dual Channel},
booktitle = {18th USENIX Symposium on Networked Systems Design and Implementation (NSDI 21)},
year = {2021},
isbn = {978-1-939133-21-2},
pages = {457--470},
url = {},
publisher = {USENIX Association},
month = apr

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