The Needed Input Data for Accurate On-line Signature Verification : The relevance of pressure and pen inclination for on-line signature verification

Abstract: Signatures have been used to authenticate documents and transactions for over 1500 years and are still being used today. In this project a method for verifying signatures written on a tablet has been developed and tested in order to test whether pressure information is vital for a well performing on-line signature verification systems. First a background study was conducted to learn about the state-of-the-art methods and what features several research systems used, then the method was developed. The method is a Dynamic Time Warp with 8 local features, 2 of them were pressure values or derived from pressure, and 1 global feature. The developed method was tested on SUSig visual corpus containing signatures from 94 persons. The Equal Error Rate (EER) when not using pressure was 5.39 % for random forgeries and 3.24 % for skilled forgeries. EER when using pressure was 5.19 % for random forgeries and 2.80 % for skilled forgeries. The background study concluded that pen inclination is not required for a well performing system. Considering the result of this project and the result of others, it seems that pressure information is not vital, but provide some valuable information that can be used to classify signatures more accurately.