{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T00:03:48Z","timestamp":1788307428300,"version":"build-2803163510"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T00:00:00Z","timestamp":1772064000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100009776","name":"McMaster University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100009776","id-type":"DOI","asserted-by":"crossref"}]},{"name":"OEaD Agency at the Vienna University of Technology fellowship"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents a pilot study on cross-device variability in online signature dynamics captured on consumer Samsung devices using S-Pen technology. Signature data were acquired on two devices, a Galaxy Ultra smartphone and a Galaxy Tab S6 Lite tablet, through a unified web-based interface designed to ensure consistent capture across platforms. The acquisition process recorded timestamped x\u2013y trajectories, stroke events, and pressure information when available, preserving temporal structure for dynamic analysis. Genuine signatures were systematically divided into reference and test sets, and comparisons were performed under intra-device conditions (enrollment and verification on the same device) and cross-device conditions (enrollment and verification on different devices). Similarity was evaluated using Dynamic Time Warping (DTW) on multivariate time series, with analysis focused on how differences in form factor and writing area influence signature behavior. This problem is directly relevant to mobile biometric authentication workflows, where users frequently enroll on one device and later verify on another; under this mismatch scenario, reduced separability between genuine and impostor scores can affect decision reliability. Consistent with this interpretation, the results show lower dissimilarity in intra-device comparisons and higher distances with ROC degradation under cross-device mismatch. These findings provide exploratory evidence that device heterogeneity is a practical factor in mobile signature verification and support the need for cross-device-aware design in authentication systems used for digital transactions and document authorization in real-world mobile environments.<\/jats:p>","DOI":"10.3390\/s26051451","type":"journal-article","created":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T09:31:32Z","timestamp":1772098292000},"page":"1451","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["S-Pen Technology and Online Signatures: Cross-Device Variability and Its Implications for Mobile Biometric Authentication"],"prefix":"10.3390","volume":"26","author":[{"given":"Gerardo","family":"Reyes-Garc\u00eda","sequence":"first","affiliation":[{"name":"Faculty of Science, Universidad Aut\u00f3noma de San Luis Potos\u00ed, San Luis Potos\u00ed 78217, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6317-3510","authenticated-orcid":false,"given":"Abel","family":"Garcia-Barrientos","sequence":"additional","affiliation":[{"name":"Faculty of Science, Universidad Aut\u00f3noma de San Luis Potos\u00ed, San Luis Potos\u00ed 78217, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2115-0097","authenticated-orcid":false,"given":"Ernesto","family":"Zambrano-Serrano","sequence":"additional","affiliation":[{"name":"Facultad de Ingenier\u00eda Mec\u00e1nica y El\u00e9ctrica, Universidad Aut\u00f3noma de Nuevo Le\u00f3n, San Nicol\u00e1s de los Garza 66455, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4748-3500","authenticated-orcid":false,"given":"Ignacio","family":"Algredo-Badillo","sequence":"additional","affiliation":[{"name":"Computer Science Department, SECIHTI-INAOE, Tonantzintla 72840, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Yeung, D.-Y., Chang, H., Xiong, Y., George, S., Kashi, R., Matsumoto, T., and Rigoll, G. (2004, January 15\u201317). SVC2004: First International Signature Verification Competition. Proceedings of the International Conference on Biometric Authentication, Hong Kong, China.","DOI":"10.1007\/978-3-540-25948-0_3"},{"key":"ref_2","unstructured":"Kholmatov, T., and Yanikoglu, B. (2006, January 5\u20137). SUSIG: An online signature database suitable for biometric research. Proceedings of the International Conference on Biometrics, Hong Kong, China."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1049\/ip-vis:20031078","article-title":"MCYT baseline corpus: A bimodal biometric database","volume":"150","author":"Simon","year":"2003","journal-title":"IEE Proc.-Vis. Image Signal Process."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2325","DOI":"10.1016\/j.patrec.2007.07.012","article-title":"HMM-based on-line signature verification: Feature extraction and signature modeling","volume":"40","author":"Fierrez","year":"2007","journal-title":"Pattern Recognit."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2400","DOI":"10.1016\/j.patrec.2005.04.017","article-title":"Identity authentication using improved online signature verification method","volume":"26","author":"Kholmatov","year":"2005","journal-title":"Pattern Recognit. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2483","DOI":"10.1016\/j.patrec.2005.05.005","article-title":"A comparative study on the consistency of features in on-line signature verification","volume":"26","author":"Lei","year":"2005","journal-title":"Pattern Recognit. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/0031-3203(89)90059-9","article-title":"Automatic signature verification and writer identification\u2014The state of the art","volume":"22","author":"Plamondon","year":"1989","journal-title":"Pattern Recognit."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1109\/TSMCC.2008.923866","article-title":"Automatic signature verification: The state of the art","volume":"38","author":"Impedovo","year":"2008","journal-title":"IEEE Trans. Syst. Man Cybern. C"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1109\/TCSVT.2003.818349","article-title":"An introduction to biometric recognition","volume":"14","author":"Jain","year":"2004","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1142\/S0218001494000346","article-title":"Automatic signature verification: The state of the art\u20141989\u20131993","volume":"8","author":"Leclerc","year":"1994","journal-title":"Int. J. Pattern Recognit. Artif. Intell."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1109\/5.554220","article-title":"Automatic on-line signature verification","volume":"85","author":"Nalwa","year":"1997","journal-title":"Proc. IEEE"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1109\/34.824821","article-title":"Online and offline handwriting recognition: A comprehensive survey","volume":"22","author":"Plamondon","year":"2000","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1109\/34.506415","article-title":"Reliable on-line human signature verification systems","volume":"18","author":"Lee","year":"1996","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1109\/TPAMI.2003.1177152","article-title":"Visual identification by signature tracking","volume":"25","author":"Munich","year":"2003","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_15","unstructured":"Nelson, N., and Kishon, E. (1991, January 13\u201316). Use of dynamic features for signature verification. Proceedings of the IEEE International Conference on Systems, Man, and Cybernetics, Charlottesville, VA, USA."},{"key":"ref_16","unstructured":"Pacut, A., and Czajka, A. (2001, January 15\u201319). Recognition of human signatures. Proceedings of the IEEE International Joint Conference on Neural Networks (IJCNN), Washington, DC, USA."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Ortega-Garcia, J., Fi\u00e9rrez-Aguilar, J., Martin-Rello, J., and Gonzalez-Rodriguez, J. (2003, January 9\u201311). Complete signal modeling and score normalization for function-based dynamic signature verification. Proceedings of the Audio- and Video-Based Biometric Person Authentication (AVBPA), Guildford, UK.","DOI":"10.1007\/3-540-44887-X_77"},{"key":"ref_18","unstructured":"Martin, J., Kandasamy, N., Greenberg, D.P., and Pardo, J.T. (1997, January 22\u201325). The DET curve in assessment of decision task performance. Proceedings of the Eurospeech, Rhodes, Greece."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1007\/s10044-005-0016-4","article-title":"On-line signature verification based on NCA and PCA","volume":"8","author":"Li","year":"2006","journal-title":"Pattern Anal. Appl."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Martens, R., and Claesen, L. (1996, January 25\u201329). On-line signature verification by dynamic time-warping. Proceedings of the International Conference on Pattern Recognition (ICPR), Vienna, Austria.","DOI":"10.1109\/ICPR.1996.546791"},{"key":"ref_21","unstructured":"Dolfing, J., Aarts, E., and Van Oosterhout, H. (1998, January 16\u201320). On-line signature verification with hidden Markov models. Proceedings of the International Conference on Pattern Recognition (ICPR), Brisbane, Australia."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1049\/iet-bmt.2013.0081","article-title":"Mobile signature verification: Feature robustness and performance evaluation","volume":"3","author":"Fierrez","year":"2014","journal-title":"IET Biom."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1145\/3274658","article-title":"A Perspective Analysis of Handwritten Signature Technology","volume":"51","author":"Diaz","year":"2019","journal-title":"ACM Comput. Surv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.patrec.2012.06.004","article-title":"Recent developments in the kinematic theory of rapid human movement","volume":"35","author":"Plamondon","year":"2014","journal-title":"Pattern Recognit. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1016\/j.humov.2009.01.005","article-title":"Studying the variability of handwriting patterns using the kinematic theory","volume":"28","author":"Djioua","year":"2009","journal-title":"Hum. Mov. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1520\/JFS15447J","article-title":"Individuality of handwriting","volume":"47","author":"Srihari","year":"2002","journal-title":"J. Forensic Sci."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Wu, X., Kimura, A., Iwana, B.K., Uchida, S., and Kashino, K. (2019, January 20\u201325). Deep Dynamic Time Warping: End-to-End Local Representation Learning for Online Signature Verification. Proceedings of the ICDAR, Sydney, Australia.","DOI":"10.1109\/ICDAR.2019.00179"},{"key":"ref_28","unstructured":"Yuan, H.J., Zhang, H., and Yin, F. (2025). Online Handwritten Signature Verification Based on Temporal-Spatial Graph Attention Transformer. arXiv."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1109\/TASSP.1978.1163055","article-title":"Dynamic programming algorithm optimization for spoken word recognition","volume":"26","author":"Sakoe","year":"1978","journal-title":"IEEE Trans. Acoust. Speech Signal Process."},{"key":"ref_30","unstructured":"Rabiner, L., and Juang, B.-H. (1993). Fundamentals of Speech Recognition, Prentice-Hall."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/5\/1451\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T05:20:48Z","timestamp":1772256048000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/5\/1451"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,26]]},"references-count":30,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["s26051451"],"URL":"https:\/\/doi.org\/10.3390\/s26051451","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,26]]}}}