EarEcho: Using Ear Canal Echo for Wearable Authentication

Smart wearable devices have recently become one of the major technological trends and been widely adopted by the general public. Wireless earphones, in particular, have seen a skyrocketing growth due to its great usability and convenience. With the goal of seeking a more unobtrusive wearable authentication method that the users can easily use and conveniently access, in this study we present EarEcho as a novel, affordable, user-friendly biometric authentication solution. EarEcho takes advantages of the unique physical and geometrical characteristics of human ear canal and assesses the content-free acoustic features of in-ear sound waves for user authentication in a wearable and mobile manner. We implemented the proposed EarEcho on a proof-of-concept prototype and tested it among 20 subjects under diverse application scenarios. We can achieve a recall of 94.19% and precision of 95.16% for one-time authentication, while a recall of 97.55% and precision of 97.57% for continuous authentication. EarEcho has demonstrated its stability over time and robustness to cope with the uncertainties on the varying background noises, body motions, and sound pressure levels.