A Real-Time In-Air Signature Biometric Technique Using a Mobile Device Embedding an Accelerometer

In this article an in-air signature biometric technique is proposed. Users would authenticate themselves by performing a 3-D gesture invented by them holding a mobile device embedding an accelerometer. All the operations involved in the process are carried out inside the mobile device, so no additional devices or connections are needed to accomplish this task. In the article, 34 different users have invented and repeated a 3-D gesture according to the biometric technique proposed. Moreover, three forgers have attempted to falsify each of the original gestures. From all these in-air signatures, an Equal Error Rate of 2.5% has been obtained by fusing the information of gesture accelerations of each axis X-Y-Z at decision level. The authentication process consumes less than two seconds, measured directly in a mobile device; so it can be considered as "real-time".