Imitation-Resistant Passive Authentication Interface for Stroke-Based Touch Screen Devices

Masashi Kudo*, Hayato Yamana

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Today’s widespread use of stroke-based touchscreen devices creates numerous associated security concerns and requires efficient security measures in response. We propose an imitation-resistant passive authentication interface for stroke-based touch screen devices employing classifiers for each individual stroke, which is evaluated with respect to 26 features. For experimental validation, we collect stroke-based touchscreen data from 23 participants containing target and imitation stroke patterns using a photo-matching game in the form of an iOS application. The equal error rate (EER), depicting the rate at which false rejection and false acceptance of target and imitator strokes are equal, is assumed as an indicator of the classification accuracy. Leave-one-out cross-validation was employed to evaluate the datasets based on the mean EER. For each cross-validation, one out of the two target datasets, an imitator dataset, and the remaining 20 imitator datasets were selected as genuine data, imitator test data, and imitator training data, respectively. Our results confirm stroke imitation as a serious threat. Among the 26 stroke features evaluated in terms of their imitation tolerance, the stroke velocity was identified as the most difficult to imitate. Dividing classifiers based on the stroke direction was found to further contribute to classification accuracy.

Original languageEnglish
Title of host publicationHCI International 2020 - Posters - 22nd International Conference, HCII 2020, Proceedings
EditorsConstantine Stephanidis, Margherita Antona
Number of pages8
ISBN (Print)9783030507312
Publication statusPublished - 2020
Event22nd International Conference on Human-Computer Interaction, HCII 2020 - Copenhagen, Denmark
Duration: 2020 Jul 192020 Jul 24

Publication series

NameCommunications in Computer and Information Science
Volume1226 CCIS
ISSN (Print)1865-0929
ISSN (Electronic)1865-0937


Conference22nd International Conference on Human-Computer Interaction, HCII 2020


  • Biometrics
  • Continuous authentication
  • Imitation
  • Passive authentication
  • Touch screen device

ASJC Scopus subject areas

  • Computer Science(all)
  • Mathematics(all)


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