International Workshop on Mobile Security

Research Article

On-line Signature Verification on a Mobile Platform

  • @INPROCEEDINGS{10.1007/978-3-642-29336-8_28,
        author={Nesma Houmani and Sonia Garcia-Salicetti and Bernadette Dorizzi and Mounim El-Yacoubi},
        title={On-line Signature Verification on a Mobile Platform},
        proceedings={International Workshop on Mobile Security},
        proceedings_a={MOBILE SECURITY},
        keywords={Online signature verification PDA device Mobile conditions Hidden Markov Models},
  • Nesma Houmani
    Sonia Garcia-Salicetti
    Bernadette Dorizzi
    Mounim El-Yacoubi
    Year: 2012
    On-line Signature Verification on a Mobile Platform
    DOI: 10.1007/978-3-642-29336-8_28
Nesma Houmani1,*, Sonia Garcia-Salicetti1,*, Bernadette Dorizzi1,*, Mounim El-Yacoubi1,*
  • 1: Institut Telecom; Telecom SudParis; Intermedia Team
*Contact email:,,,


This paper concerns the implementation of our online signature verification system on a mobile device. Verification involves confirming or denying a person‘s claimed identity. Our system is based on a Hidden Markov Model and outputs two complementary scores: the first one is related to the likelihood given by the HMM of the claimed identity; the second one is related to the segmentation given by such an HMM on the input signature. A claimed identity is confirmed when the arithmetic mean of the two scores obtained on such an input signature is higher than a threshold. Also, a personal normalization of the local parameters of the signature is carried out to make the system robust to changes of platforms. A patent was submitted with special emphasis on the latter claim. This system is implemented on a mobile platform PDA Qtek 2020 ARM 400 MHz. An acquisition interface is developed allowing an enrollment step of a person by acquisition of 5 of his/her signatures, and a verification step of a given signature of a registered person. Enrolment speed depends on the complexity of the signature, while verification is performed in real time. Performance assessment of our system, carried out on two databases acquired on a PDA, shows a degradation of system performance on mobile platform compared to a fixed platform. In order to improve the performance in the case of mobility, we propose a strategy for enhancing the quality of the reference signatures at the enrolment phase.