SECURE FINGERPRINT VERIFICATION BASED ON IMAGE PROCESSING SEGMENTATION USING COMPUTATIONAL GEOMETRY ALGORITHMS M .Poulos E.Magkos V. Chrissikopoulos N. Alexandris marios.p@usa.net emagos@unipi.gr vchris@ionio.gr alexandr@unipi.gr Department of Informatics University of Piraeus 80 Karaoli & Dimitriou str., Piraeus 18534, Greece Department of Archives and Library Sciences, University of Ionian, Palea Anaktora, Corfu 49100, Greece Department of Informatics University of Piraeus 80 Karaoli & Dimitriou str., Piraeus 18534, Greece ABSTRACT In this paper, fingerprint segmentation for secure Internet verification purposes is investigated. The novel application of computational geometry algorithms in the fingerprint segmentation stage showed that the extracted feature (characteristic polygon) may be used as a secure and accurate method for fingerprint-based verification over the Internet. On the other hand the proposed method promisingly allows very small false acceptance and false rejection rates, as it is based on specific segmentation. KEY WORDS Computational Geometry, Security, Fingerprint, Verification, Image Segmentation 1. INTRODUCTION Biometry, as the science of studying mathematical or statistical properties in physiological and behavioural human characteristics, is widely used in forensic and non- forensic applications in security field such as remote computer access, access control to physical sites, transaction authorization etc. In this paper the problem of fingerprint verification via the Internet is investigated. Specifically, the method that is used for the above purpose is based on a traditional finger scanning technique, involving the analysis of small unique marks of the finger image known as minutiae. Minutiae points are the ridge endings or bifurcations branches of the finger image. The relative position of these minutiae is used for comparison, and according to empirical studies, two individuals will not have eight or more common minutiae. [1,2]. A typical live-scan fingerprint will contain 30-40 minutiae. Other systems analyse tiny sweat pores on the finger that, in the same way as minutiae, are uniquely positioned. Finger scanning is not immune to environmental disturbance. As the image is captured when the finger is touching the scanner device it is possible that dirt, condition of the skin, pressure and alignment or rotation of the finger all affect the quality of the fingerprint. Furthermore, such methods may be subject to attacks by hackers when biometric features are transferred via Internet [3]. In this paper we developed a method, which addresses the problem of the rotation and alignment of the finger position. The proposed method is based on computational geometry algorithms. The advantages of this method are based on a novel processing method using specific extracted features, which may be characterized as unique to each person. These features depend exclusively on the pixels brightness degree for the fingerprint image, in contrast to traditional methods where features are extracted using techniques such as edge, minutiae points and ridges detection. Specifically, these feature express a specific geometric area (convex layer) in which the dominant brightness value of the fingerprint ranges. What makes biometrics useful for many applications is that they can be stored in a database. From a security point of view, fingerprints and biological data in general constitute sensitive information that has to be protected. Towards this direction, our method isolates a very small fraction of the user’s biological data, and only this fraction is stored for future reference. This can also improve the overall efficiency and bandwidth effectiveness of the system. 2. METHOD In brief, the proposed method is described in the following steps: