A Secure ID Card based Authentication System using Watermarking

This paper shows a watermark-based approach to protect digital identity documents against a Print-Scan (PS) attack. We propose a secure ID card authentication system based on watermarking. For authentication purposes, a user/customer is asked to upload a scanned picture of a passport or ID card through the internet to fulfill a transaction online. To provide security in online ID card submission, we need to robustly encode personal information of ID card’s holder into the card itself, and then extract the hidden information correctly in a decoder after the PS operation. The PS operation imposes several distortions, such as geometric, rotation, and histogram distortion, on the watermark location, which may cause the loss of information in the watermark. An online secure authentication system needs to first eliminate the distortion of the PS operation before decoding the hidden data. This study proposes five preprocessing blocks to remove the distortions of the PS operation: filtering, localization, binarization, undoing rotation, and cropping. Experimental results with 100 ID cards showed that the proposed online ID card authentication system has an average accuracy of 99% in detecting hidden information inside ID cards after the PS process. The innovations of this study are the implementation of an online watermark-based authentication system which uses a scanned ID card picture without any added frames around the watermark location, unlike previous systems.