A New System for Secure Handwritten Signing of Documents

Handwritten Signature Verification (HSV) is a natural and trusted method for user identity verification. HSV can be classified into two main categories: offline and online HSV. Offline systems take handwritten signatures from scanned documents, while online systems use specific hardware (e.g., pen tablets) to register pen movements during the act of signing. Online HSV systems may embed signatures (including the signature dynamics) into digital documents. Unfortunately, during their lifetime documents may be repeatedly printed and scanned, and digital to paper conversions may result in loosing the signature dynamics. The main contribution of this work is a new HSV system for secure handwritten signing of documents. First, we illustrate how to verify handwritten signatures so that signature dynamics can be processed during verification of every type of document (both paper and digital documents). Secondly, we show how to embed features extracted from handwritten signatures within the documents themselves, so that no remote signature database is needed. To accomplish the embedding task, we make use of 2D barcodes. The main challenge here is to be able to store the signature dynamics within the limited capacity of barcodes. Thirdly, we propose a method for the verification of signature dynamics which is compatible to a wide range of mobile devices so that no special hardware is needed. The main challenge here is to achieve a high verification performance, despite constrains due to the limited computational resources and pressure accuracy of mobile phones. We address the trade-off between discrimination capabilities of the system and the storage size of the signature model. Towards this end, we report the results of an experimental evaluation of our system on different signature datasets.