Showing papers by "Nalini K. Ratha published in 2007"

Generating Cancelable Fingerprint Templates

Abstract: Biometrics-based authentication systems offer obvious usability advantages over traditional password and token-based authentication schemes. However, biometrics raises several privacy concerns. A biometric is permanently associated with a user and cannot be changed. Hence, if a biometric identifier is compromised, it is lost forever and possibly for every application where the biometric is used. Moreover, if the same biometric is used in multiple applications, a user can potentially be tracked from one application to the next by cross-matching biometric databases. In this paper, we demonstrate several methods to generate multiple cancelable identifiers from fingerprint images to overcome these problems. In essence, a user can be given as many biometric identifiers as needed by issuing a new transformation "key". The identifiers can be cancelled and replaced when compromised. We empirically compare the performance of several algorithms such as Cartesian, polar, and surface folding transformations of the minutiae positions. It is demonstrated through multiple experiments that we can achieve revocability and prevent cross-matching of biometric databases. It is also shown that the transforms are noninvertible by demonstrating that it is computationally as hard to recover the original biometric identifier from a transformed version as by randomly guessing. Based on these empirical results and a theoretical analysis we conclude that feature-level cancelable biometric construction is practicable in large biometric deployments

Anonymous and Revocable Fingerprint Recognition

Abstract: Biometric identification has numerous advantages over conventional ID and password systems; however, the lack of anonymity and revocability of biometric templates is of concern. Several methods have been proposed to address these problems. Many of the approaches require a precise registration before matching in the anonymous domain. We introduce binary string representations of fingerprints that obviates the need for registration and can be directly matched. We describe several techniques for creating anonymous and revocable representations using these binary string representations. The match performance of these representations is evaluated using a large database of fingerprint images. We prove that given an anonymous representation, it is computationally infeasible to invert it to the original fingerprint, thereby preserving privacy. To the best of our knowledge, this is the first linear, anonymous and revocable fingerprint representation that is implicitly registered.

Introduction to the Special Issue on Recent Advances in Biometric Systems [Guest Editorial]

Abstract: The fourteen papers in this special section are devoted to recent advancements in biometric systems and application devices.

Privacy management in imaging system

Abstract: The system and method obscures descriptive image information about one or more images. The system comprises a selector for selecting the descriptive image information from one or more of the images, a transformer that transforms the descriptive information into a transformed state, and an authorizer that provides authorization criteria with the image. In a preferred embodiment, the transformed state is the respective image encoded with the descriptive information. The descriptive information can be obscured so that the descriptive information in the transformed state can be decoded only if one or more authorization inputs satisfy the authorization criteria.

Method, Apparatus and Computer Program Product Implementing Anonymous Biometric Matching

Abstract: Method, apparatus and computer program product compare biometrics in an anonymous manner. A first collection of biometrics is transformed using a first cancelable non-invertible biometric transform to create a first collection of transformed biometrics. A second collection of biometrics is transformed using the first cancelable non-invertible biometric transform to create a second collection of transformed biometrics. The first and second collection of transformed biometrics are then compared in the transformed domain to determine if any of the transformed biometrics from the first collection match any of the transformed biometrics from the second collection. If a match is found, the parties respectively maintaining the first and second collections of biometrics exchange information confidential nature of the biometrics are maintained by the entities responsible for the collections, since the biometrics are not compared in an untransformed state.

Security and Accuracy Trade-off in Anonymous Fingerprint Recognition

Abstract: The security, lack of anonymity and revocability of the biometric template are critical issues that need to be addressed in order to vindicate the viability of biometric based authentication systems. Several methods have been proposed to address these problems. However, most of these methods offer lower accuracies than the base system where the template is insecure. This is because in most systems the gain in the security is achieved as a result of loss in non-redundant information. In this paper, we describe tradeoff between accuracy of an anonymous system and the security of the biometrics system. As a case study we start with a highly secure representation of a fingerprint. Then we describe several methods and show experimental results proving that every time we add more information to the secure representation, the accuracy increases, however valuable information is revealed to an adversary. We propose, via a k-trial attack model, how the trade-off can be complemented by another security policy such as an account lockout after a given number of attempts.

Guest Editorial: Special Issue on Human Detection and Recognition

Abstract: The 12 regular papers and three correspondences in this special issue focus on human detection and recognition. The papers represent gait, face (3-D, 2-D, video), iris, palmprint, cardiac sounds, and vulnerability of biometrics and protection against the spoof attacks.

Security andAccuracy Trade-off inAnonymous Fingerprint Recognition

Abstract: Thesecurity, lackofanonymity andrevocability ofthebiometric template arecritical issues thatneedtobe addressed inordertovindicate theviability ofbiometric based authentication systems. Several methods havebeenproposed to address these problems. However, mostofthese methods offer loweraccuracies thanthebasesystem wherethetemplate is insecure. Thisisbecause inmostsystems thegaininthesecurity isachieved asaresult oflossinnon-redundant information. Inthispaper, we describe tradeoff between accuracy ofan anonymous system andthesecurity ofthebiometrics system. Asacasestudywestart withahighly secure representation ofafingerprint. Thenwedescribe several methods andshow experimental results proving thateverytimewe addmore information tothesecure representation, theaccuracy increases, however valuable information isrevealed toanadversary. We propose, viaak-trial attack model, howthetrade-off canbe complemented byanother security policy suchasanaccount lockout after agiven numberofattempts. I.INTRODUCTION Biometric systems suchasfingerprint havelimited ac- curacies. Thisisfurther accentuated whenthematching is performed inasecure mannersoasnottoreveal information about theactual biometric. Suchsystems called, anonymous, cancelable orrevocable biometric systems often suffer from loweraccuracies ascompared totheplain counterparts, if anyexist. Inthis paper wedescribe amethod toimprove on theaccuracies ofaregistration freeanonymous fingerprint verification system. We alsodiscuss thesecurity trade-offs madetherein. Theproposed methods havebeentested using areal-time datasetfordifferent cases. InSection IIwepresent abrief discussion oftherecent worksintheareaofanonymous biometrics. Wedescribe ouranonymous fingerprint matching representation inbrief inSection IIIandthemodifications inSection IV.We alsopresent theexperimental analysis inSection IVanddiscuss theprivacy concerns witheach modification inSection V.We drawconclusions andbriefly discuss future research directions inSection VI.

Large-Scale Biometric Identification: Challenges and Solutions.

Abstract: In addition to law enforcement applications, many civil applications will require biometrics-based identification systems and a large percentage is predicted to rely on fingerprints as an identifer. Even though fingerprint as a biometric has been used in many identification applications, mostly these applications have been semi-automatic. The results of such systems often require to be validated by human experts. With the increased use of biometric identification systems in many realtime applications, the challenges for large-scale biometric identification are significant both in terms of improving accuracy and response time. In this paper, we briey review the tools, terminology and methods used in large-scale biometrics identification applications. The performance of the identification algorithms need to be significantly improved to successfully handle millions of persons in the biometrics database matching thousands of transactions per day.