Exploring a secure device pairing using human body as a conductor

Recent research has been exploring ways to streamline device pairing by introducing touch-to-access that minimizes user interaction. It generates pairing keys by extracting features from a shared information source to ascertain if two devices are being held by the same person. While these solutions focus on verifying the authenticity of the device, they do not consider the legitimacy and pairing intent of the device holder. Moreover, the pairing keys exchanged over an open wireless link may be susceptible to eavesdropping attacks. In this paper, we propose a secure device pairing mechanism that utilizes the unique electrical responses of the human body to generate and transmit user-specific pairing keys, ensuring both the user's legitimacy and pairing intent while also improving key transmission reliability. We accomplish this by using the device's built-in microphone to capture ambient sound as entropy and converting it into an electrical signal transmitted by the body for device pairing. We have built a prototype and conducted extensive experiments with 31 participants to evaluate its security and usability. The results demonstrate that our proposed mechanism offers a more secure and reliable option for user-specific pairing keys, contributing to the field of device pairing.