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Thesis Proposal Towards Template Security for Iris- Based Biometric Systems by Marwa Fouad Thesis submitted to the Faculty of Graduate and Postdoctoral Studies in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Electrical & Computer Engineering School of Electrical Engineering and Computer Science University of Ottawa © Marwa Fouad, Ottawa, Canada, 2012 Abstract Personal identity refers to a set of attributes (e.g., name, social insurance number, etc.) that are associated with a person. Identity management is the process of creating, maintaining and destroying identities of individuals in a population. Biometric technologies are technologies developed to use statistical analysis of an individual’s biological or behavioral traits to determine his identity. Biometrics based authentication systems offer a reliable solution for identity management, because of their uniqueness, relative stability over time and security (among other reasons). Public acceptance of biometric systems will depend on their ability to ensure robustness, accuracy and security. Although robustness and accuracy of such systems are rapidly improving, there still remain some issues of security and balancing it with privacy. While the uniqueness of biometric traits offers a convenient and reliable means of identification, it also poses the risk of unauthorized cross-referencing among databases using the same biometric trait. There is also a high risk in case of a biometric database being compromised, since it’s not possible to revoke the biometric trait and re-issue a new one as is the case with passwords and smart keys. This unique attribute of biometric based authentication system poses a challenge that might slow down public acceptance and the use of biometrics for authentication purposes in large scale applications. In this research we investigate the vulnerabilities of biometric systems focusing on template security in iris-based biometric recognition systems. The iris has been well studied for authentication purposes and has been proven accurate in large scale applications in several airports and border crossings around the world. The most widely accepted iris recognition systems are based on Daugman’s model that creates a binary iris template. In this research we develop different systems using watermarking, bio- cryptography as well as feature transformation to achieve revocability and security of binary templates in iris based biometric authentication systems, while maintaining the performance that enables widespread application of these systems. All algorithms developed in this research are applicable on already existing biometric authentication systems and do not require redesign of these existing, well established iris-based authentication systems that use binary templates. II Acknowledgements I would like to seize this opportunity to pay tribute to all those who have contributed, one way or another, to the completion of this work, which marks another important milestone in my life. First of all, I would like to express my heartfelt thanks to Prof. Emil Petriu taking an interest in my work and having the initiative to assume a guidance role, and helping me to submit this thesis. I would also like to express my profound gratitude and great indebtedness to Prof. Abdulmotaleb El Saddik, for his benevolent supervision of my doctorate thesis. I thank him for encouraging and believing in me. His continuous support and constructive criticism, his invaluable advice, guidance, as well as his understanding were of great value to me. But most of all, I thank him for his patience with me through the highs and lows of this research time. I deeply appreciate the help and contributions received from many people during this project: I am very grateful to Prof. Jiying Zhao. Your kindness and helpfulness will forever remain imprinted in my mind. I would also like to gratefully acknowledge the contributions of Fawaz A Alsulaiman. I really appreciate your help in a field that was new to me. I dedicate this thesis to my husband, my supporting pillar, whose continual back-up and loving support was of great value in accomplishing this work. I also dedicate this thesis to my children; watching you grow is the greatest pleasure in my life and raising you has taught me so much about life and about myself. Last but not least, I wish to repay the debt of gratitude I owe my beloved parents, my mentors and teachers, my idols and my heroes; for years of encouragement and for their strong belief in me. I owe them great appreciation for what I have learned and what I have achieved. I wish you were here with me, mom, but you’re always on my mind and your love, support and wisdom are forever engraved in my heart and mind. God bless your soul and may you rest in peace. III Contents ABSTRACT ..................................................................................................................... II ACKNOWLEDGEMENTS ................................................................................................ III CONTENTS ................................................................................................................... IV LIST OF FIGURES .......................................................................................................... VII LIST OF TABLES ............................................................................................................. X LIST OF ACRONYMS ..................................................................................................... XI CHAPTER 1 INTRODUCTION ...................................................................................... 1 1.1 BIOMETRIC SECURITY ................................................................................................ 1 1.2 MOTIVATION .......................................................................................................... 7 1.3 GOALS, REQUIREMENTS AND CHALLENGES ................................................................... 9 1.4 THESIS OVERVIEW.................................................................................................. 10 1.5 CONTRIBUTIONS .................................................................................................... 11 1.6 SCHOLARLY OUTPUT ............................................................................................... 12 CHAPTER 2 FEATURE TRANSFORMATION ............................................................... 13 2.1 IRIS TEMPLATE CREATION ........................................................................................ 13 2.1.1 Iris Segmentation ...................................................................................... 17 2.1.2 Iris Normalization ...................................................................................... 18 2.1.3 Feature Encoding ...................................................................................... 19 2.1.4 Iris Code Matching .................................................................................... 20 2.1.5 Performance Evaluation ........................................................................... 22 2.2 INVERTIBLE FEATURE TRANSFORMATION .................................................................... 23 2.3 NON-INVERTIBLE FEATURE TRANSFORMATION ............................................................ 23 2.4 FEATURE TRANSFORMATION EVALUATION .................................................................. 24 2.4.1 Iris Shuffling .............................................................................................. 24 2.4.2 Iris Folding ................................................................................................. 25 2.4.3 Row Shifting and Permutation .................................................................. 26 2.4.4 Database ................................................................................................... 27 IV 2.4.5 Parameter Values...................................................................................... 28 2.4.6 Performance ............................................................................................. 28 2.4.7 Security Analysis ....................................................................................... 33 2.4.8 Conclusion................................................................................................. 34 CHAPTER 3 BIOMETRIC CRYPTOSYSTEMS ............................................................... 36 3.1 KEY-GENERATING .................................................................................................. 37 3.2 KEY-BINDING ........................................................................................................ 39 3.3 PROPOSED KEY-BINDING SYSTEM ............................................................................. 45 3.3.1 Revocability ............................................................................................... 47 3.3.2 Performance ............................................................................................. 47 3.3.3 Cyclic Redundancy Check Module ............................................................ 49 3.3.4 Security Analysis ....................................................................................... 51 3.3.5 Discussion ................................................................................................. 51 3.4 PROPOSED FUZZY VAULT SYSTEM ............................................................................. 52 3.4.1 Parameter Values.....................................................................................
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