Secure cryptographic communication using ultrasound audio for frictionless payment transactions and secure conversations over a short-range human audible/inaudible spectrum


  • ArulKumaran Chandrasekaran Research and Development, Ozone Towers, Tamil Nadu, India; Research and Development, ethTV Inc, Arizona, USA



Cryptographic communication, Ultrasound audio, Payment transactions, Proximity detection, Secure conversations


Background: The aim of the study was to address these challenges by leveraging ultrasound audio as a means for secure cryptographic communication. By utilizing the human audible and inaudible audio spectrum, this approach eliminates the reliance on specialized hardware or traditional network technologies, such as bluetooth, wi-fi, NFC, or RF-based alternatives.

Methods: Various mobile phones, tablets, and POS hardware devices with basic microphones and speakers were employed to test the communication channel's performance. The sensitivity of the devices in different environments, such as retail stores or crowded venues like stadiums, was taken into account.  

Results: The results demonstrated the viability of the proposed secure cryptographic communication using ultrasound audio. Transactions, including payment processing, were successfully conducted without the need for specialized hardware or network connectivity.

Conclusions: The proposed solution offers a reliable and cost-effective method for proximity detection, verification, and frictionless transactions. By leveraging the human audible and inaudible audio spectrum, this technology eliminates the need for specialized hardware or traditional network connectivity.


Metrics Loading ...


Roesner F, Kohno T, Molnar D. Security and privacy for next-generation consumer devices. Communicat ACM. 2014;57(9):56-64.

Jana S, Sherr M, Gupta V. On the feasibility of using sound to detect physical proximity of smartphones. Proceed 4th ACM Confer Secur Priv Wireless Mob Net. 2013:1-6.

Cai L, Tan Y, Zhu L. A secure communication scheme based on ultrasound in IoT. Mob Net Applic. 2016;21(4):668-74.

Huang D, Li Q, Han G, Zhang X, Li Y. Secure communication based on dual-channel audio frequency under loud noise. Mob Net Applic. 2020;25(4):1563-72.

Chen Y, Liu S, Huang T. Secure data transmission using dual-tone multi-frequency signals over air-gap channels. IEEE Access. 2019;7:164764-73.

Guri M, Kachlon A, Hasson O, Elovici Y. GSMem: Data exfiltration from air-gapped computers over GSM frequencies. Comput Securit. 2018;78:325-37.

Zou T, Li J, Liu J. Ultrasonic communication security based on orthogonal frequency division multiplexing. IEEE Access. 2021;9:28175-83.

Guo C, Wang W. Secure and efficient audio-based communication protocol for proximity detection in IoT. J Ambi Intelligen Humaniz Comput. 2022;13(1):957-67.

Mehrabi A, Mazzoni A, Jones D, Steed A. Evaluating the user experience of acoustic data transmission. Person Ubiquit Comput. 2019;24:655-68.

NFC forum. Fact sheet: NFC is the future of “frictionless” payment, 2020. Available at: Accessed on 20 June 2023.






Original Research Articles