Title: Advanced Android covert channel attacks with novel evasion methods

Authors: Abhinav Shah; Digvijaysinh M. Rathod; Bharat Buddhadev; Jeet Rami

Addresses: School of Cyber Security and Digital Forensics, National Forensic Sciences University, Gandhinagar, India ' School of Cyber Security and Digital Forensics, National Forensic Sciences University, Gandhinagar, India ' School of Cyber Security and Digital Forensics, National Forensic Sciences University, Gandhinagar, India ' Microsoft, Hyderabad, India; School of Cyber Security and Digital Forensics, National Forensic Sciences University, Gandhinagar, India

Abstract: In the field of secure communication, establishing concealed pathways is vital for maintaining confidentiality. This study introduces innovative approaches for covert communication through audio channels, employing advanced entropy encoding and dynamic strategies in Android. The proposed method explores creative means of embedding sensitive information (device ID, contact number, and SMS) within audio files to minimise detection. By integrating state-of-the-art entropy encoding, the system achieves effective data compression and encryption, ensuring resilience against unauthorised interception. Dynamic techniques are implemented to adapt to changing environmental conditions, enhancing the robustness of the covert communication system. The paper employs novel evasion methods and covert channels techniques, including Base64 encoding, fixed-length encoding, dynamic length encoding, and Huffman encoding in Android. Comprehensive experimental results demonstrate the effectiveness of the proposed methods in terms of covert channel capacity, reliability, and resistance to detection. The android application is developed using proposed methodology and security assessment is carried out. The paper concludes by introducing various entropy and dynamic techniques, comparing their results and highlighting outcomes in covert audio communication. Findings suggest that Base64 encoding, as an evasion technique, shows shorter encoding/decoding times, higher throughput, and increased bit-carrying capacity, enabling efficient transfer of sensitive data in an audio covert channel.

Keywords: covert channel; cyber security; Android application.

DOI: 10.1504/IJESDF.2026.152248

International Journal of Electronic Security and Digital Forensics, 2026 Vol.18 No.2, pp.217 - 239

Received: 20 Mar 2024
Accepted: 30 Apr 2024
Published online: 12 Mar 2026 *

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