SetMargin Loss applied to Deep Keystroke Biometrics with Circle Packing Interpretation

This work presents a new deep learning approach for keystroke biometrics based on a novel Distance Metric Learning method (DML). DML maps input data into a learned representation space that reveals a "semantic" structure based on distances. In this work, we propose a novel DML method speci...

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Bibliographic Details
Main Authors: Morales, Aythami, Fierrez, Julian, Acien, Alejandro, Tolosana, Ruben, Serna, Ignacio
Format: Article in Journal/Newspaper
Language:unknown
Published: arXiv 2021
Subjects:
DML
Online Access:https://dx.doi.org/10.48550/arxiv.2109.00938
https://arxiv.org/abs/2109.00938
Description
Summary:This work presents a new deep learning approach for keystroke biometrics based on a novel Distance Metric Learning method (DML). DML maps input data into a learned representation space that reveals a "semantic" structure based on distances. In this work, we propose a novel DML method specifically designed to address the challenges associated to free-text keystroke identification where the classes used in learning and inference are disjoint. The proposed SetMargin Loss (SM-L) extends traditional DML approaches with a learning process guided by pairs of sets instead of pairs of samples, as done traditionally. The proposed learning strategy allows to enlarge inter-class distances while maintaining the intra-class structure of keystroke dynamics. We analyze the resulting representation space using the mathematical problem known as Circle Packing, which provides neighbourhood structures with a theoretical maximum inter-class distance. We finally prove experimentally the effectiveness of the proposed approach on a challenging task: keystroke biometric identification over a large set of 78,000 subjects. Our method achieves state-of-the-art accuracy on a comparison performed with the best existing approaches. : Papper accepted in journal Pattern Recognition