An efficient VoLTE covert timing channel for 5 G networks: RDCTC

Abbas M. K., Sandıkkaya M. T.

OPTIK, vol.270, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 270
  • Publication Date: 2022
  • Doi Number: 10.1016/j.ijleo.2022.170076
  • Journal Name: OPTIK
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, INSPEC
  • Keywords: Covert timing channels, 5G networks, VoLTE, inter-packet delays, Reorder density, Modified turbo code, Discrete Haar wavelet transform, threat model, randomness test
  • Istanbul Technical University Affiliated: Yes


Covert Channels are necessary to protect the privacy of individuals as well as to obtain confidentiality to governmental and military agencies. A novel covert timing channel is proposed with three main improvements over the existing ones: Reorder Density (RD) metric-based packet reordering that reduces exposure, introducing Modified Turbo Code (MTC) for efficient encoding, and Discrete Haar Wavelet Transform (DHWT) that increases channel reliability. A threat model is proposed and shown to be inefficient to effectively meet covert channel properties against network jitter, noise, and curious attackers that try to identify a channel exists. Run and test is applied to investigate randomness of the proposed covert channel. The proposed covert channel is adoptable to 5 G VoLTE networks. These proposed strategies significantly improve the robustness while also minimizing the detectability of covert channels in VoLTE.