SilentSign: Device-free Handwritten Signature Verification through Acoustic Sensing
Mengqi Chen, Jiawei Lin, Yongpan Zou, Rukhsana Ruby, Kaishun Wu
Abstract
Signature is one of the most prevailing identity authorization approaches. It is yet inconvenient to use in real life in the sense that a majority of existing signature verification approaches rely on additional digital signing devices. In this paper, we propose a portable device-free signature verification system named SilentSign which makes use of acoustic sensors (i.e., microphone and speaker) embedded in smart devices to enable secure and convenient signature verification service. The basic idea is to leverage acoustic signals to measure the distance variation of the tip of the pen while signing. We carefully design the signal modulation scheme, develop a phase-based distance measurement technique, and train the verification model for high performance and robustness. Compared with conventional digital signing systems, SilentSign allows users to sign more invisibly and conveniently. We conduct extensive experiments involving 35 participants to evaluate SilentSign. Results show that SilentSign can achieve 98.2% AUC and 1.25% EER.