CSI2Dig: Recovering Digit Content from Smartphone Loudspeakers Using Channel State Information

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gu, Yangyang, Li, Xianglong, Wu, Haolin, Chen, Jing, He, Kun, Du, Ruiying, Wu, Cong
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912338064441344
author Gu, Yangyang
Li, Xianglong
Wu, Haolin
Chen, Jing
He, Kun
Du, Ruiying
Wu, Cong
author_facet Gu, Yangyang
Li, Xianglong
Wu, Haolin
Chen, Jing
He, Kun
Du, Ruiying
Wu, Cong
contents Eavesdropping on sounds emitted by mobile device loudspeakers can capture sensitive digital information, such as SMS verification codes, credit card numbers, and withdrawal passwords, which poses significant security risks. Existing schemes either require expensive specialized equipment, rely on spyware, or are limited to close-range signal acquisition. In this paper, we propose a scheme, CSI2Dig, for recovering digit content from Channel State Information (CSI) when digits are played through a smartphone loudspeaker. We observe that the electromagnetic interference caused by the audio signals from the loudspeaker affects the WiFi signals emitted by the phone's WiFi antenna. Building upon contrastive learning and denoising autoencoders, we develop a two-branch autoencoder network designed to amplify the impact of this electromagnetic interference on CSI. For feature extraction, we introduce the TS-Net, a model that captures relevant features from both the temporal and spatial dimensions of the CSI data. We evaluate our scheme across various devices, distances, volumes, and other settings. Experimental results demonstrate that our scheme can achieve an accuracy of 72.97%.
format Preprint
id arxiv_https___arxiv_org_abs_2504_14812
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle CSI2Dig: Recovering Digit Content from Smartphone Loudspeakers Using Channel State Information
Gu, Yangyang
Li, Xianglong
Wu, Haolin
Chen, Jing
He, Kun
Du, Ruiying
Wu, Cong
Cryptography and Security
68T10
I.5.1
Eavesdropping on sounds emitted by mobile device loudspeakers can capture sensitive digital information, such as SMS verification codes, credit card numbers, and withdrawal passwords, which poses significant security risks. Existing schemes either require expensive specialized equipment, rely on spyware, or are limited to close-range signal acquisition. In this paper, we propose a scheme, CSI2Dig, for recovering digit content from Channel State Information (CSI) when digits are played through a smartphone loudspeaker. We observe that the electromagnetic interference caused by the audio signals from the loudspeaker affects the WiFi signals emitted by the phone's WiFi antenna. Building upon contrastive learning and denoising autoencoders, we develop a two-branch autoencoder network designed to amplify the impact of this electromagnetic interference on CSI. For feature extraction, we introduce the TS-Net, a model that captures relevant features from both the temporal and spatial dimensions of the CSI data. We evaluate our scheme across various devices, distances, volumes, and other settings. Experimental results demonstrate that our scheme can achieve an accuracy of 72.97%.
title CSI2Dig: Recovering Digit Content from Smartphone Loudspeakers Using Channel State Information
topic Cryptography and Security
68T10
I.5.1
url https://arxiv.org/abs/2504.14812