A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> Within the next year, travelers from dozens of nations may be carrying a new form of passport in response to a mandate by the United States government. The e-passport, as it is sometimes called, represents a bold initiative in the deployment of two new technologies: Radio-Frequency Identification (RFID) and biometrics. Important in their own right, e-passports are also the harbinger of a wave of next-generation ID cards: several national governments plan to deploy identity cards integrating RFID and biometrics for domestic use. We explore the privacy and security implications of this impending worldwide experiment in next-generation authentication technology. We describe privacy and security issues that apply to e-passports, then analyze these issues in the context of the International Civil Aviation Organization (ICAO) standard for e-passports. <s> BIB001 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> Details multimodal biometrics and its exceptional utility for increasingly reliable human recognition systems. Reveals the substantial advantages of multimodal systems over conventional identification methods. <s> BIB002 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> We propose the first practical and secure way to integrate the iris biometric into cryptographic applications. A repeatable binary string, which we call a biometric key, is generated reliably from genuine iris codes. A well-known difficulty has been how to cope with the 10 to 20 percent of error bits within an iris code and derive an error-free key. To solve this problem, we carefully studied the error patterns within iris codes and devised a two-layer error correction technique that combines Hadamard and Reed-Solomon codes. The key is generated from a subject's iris image with the aid of auxiliary error-correction data, which do not reveal the key and can be saved in a tamper-resistant token, such as a smart card. The reproduction of the key depends on two factors: the iris biometric and the token. The attacker has to procure both of them to compromise the key. We evaluated our technique using iris samples from 70 different eyes, with 10 samples from each eye. We found that an error-free key can be reproduced reliably from genuine iris codes with a 99.5 percent success rate. We can generate up to 140 bits of biometric key, more than enough for 128-bit AES. The extraction of a repeatable binary string from biometrics opens new possible applications, where a strong binding is required between a person and cryptographic operations. For example, it is possible to identify individuals without maintaining a central database of biometric templates, to which privacy objections-might be raised <s> BIB003 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> In this paper we present a scheme for building a logging- trail for processes related to eGovernment services. A citizen can reconstruct the trail of such a process and verify its status if he is the subject of that process. Reconstruction is based on hand-overs, special types of log events, that link data stored by multiple logging servers, which are not necessarily trusted. Our scheme is privacy-friendly in the sense that only the authorised subject, i.e. the citizen, can link the different log entries related to one specific process. The scheme is also auditable; it allows logging servers to show that they behave according to a certain policy. <s> BIB004 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> Pervasive computing environments present unique challenges related to specific aspects of security and multimodality (SMPE). In fact, the accessibility of such an environment can be certainly improved using natural interfaces and multimodal interaction systems, which offer users the freedom to select one of multiple modes of interaction with services. They also offer users the opportunity to break through barriers on human–computer interaction making communication intuitive and spontaneous. On the other hand, while extending and facilitating the ways of accessing the environment, security threads arise and the environment must be properly instrumented in order to protect itself from malicious attacks and/or from erroneous actions performed by non-expert users. We received eighteen manuscripts. After the pre-review process, fourteen manuscripts were selected for the first review. Eight manuscripts were finally selected for this Special Issue after the first, second, and third review processes. Each manuscript selected from the pre-review was blindly reviewed by at least three reviewers consisting of guest editors and external reviewers. <s> BIB005 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> The term biometrics refers to “automated recognition of individuals based on their behavioral and biological characteristics” (ISO/IEC JTC1 SC37). Several physiological (static) as well as behavioral (non-static) biometric characteristics have been exploited (Jain, Flynn & Ross, 2008) such as fingerprints, iris, face, hand, voice, gait, keystroke dynamics, etc., depending on distinct types of applications (see Figure 1). Biometric traits are acquired applying adequate sensors and distinctive feature extractors are utilized in order to generate a biometric template (reference data) in the enrollment process. During verification (authentication process) or identification (identification can be handled as a sequence of biometric comparisons against the enrollment records in a reference databse) the system processes another biometric measurement from which an according template is extracted and compared against the stored template(s) yielding acceptance/ rejection or hit/ no-hit, respectively. The presented work is motivated by very recent advances in the fields of multi-biometric recognition (Ross et al., 2006) and biometric template protection (Rathgeb & Uhl, 2011). Automatic recognition systems based on a single biometric indicator often have to contend with unacceptable error rates (Ross & Jain, 2003). Multi-biometric systems have improved the accuracy and reliability of biometric systems (Ross et al., 2006). Biometric vendors are already deploying multi-biometric systems (e.g. fingerprint and finger vein by SAFRAN Morpho1) and multi-biometric recognition is performed on large-scale datasets (e.g. within the Aadhaar project (Unique Identification Authority of India, 2012) by the Unique Identification Authority of India (UIDAI)). However, security of multi-biometric templates is especially crucial as they contain information regarding multiple traits of the same subject (Nagar et al., 2012). The leakage of any kind of template information to unauthorized individuals constitutes serious security and privacy risks, e.g. permanent tracking of subjects without consent (Ratha et al., 2001) or reconstruction of original biometric traits (e.g. fingerprints (Cappelli et al., 2007) or iris textures (Venugopalan & Savvides, 2011)) might become a realistic threat. Therefore, biometric template protection technologies have been developed in order to protect privacy and integrity of stored biometric data. However, so far, template protection schemes which provide provable security/ privacy, and achieve practical recognition rates have remained elusive, even on small datasets. This bookchapter provides a comprehensive overview of <s> BIB006 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> This article presents a tutorial overview of the application of techniques of secure two-party computation (also known as secure function evaluation) to biometric identification. These techniques enable to compute biometric identification algorithms while maintaining the privacy of the biometric data. This overview considers the main tools of secure two-party computations such as homomorphic encryption, garbled circuits (GCs), and oblivious transfers (OTs) and intends to give clues on the best practices to secure a biometric identification protocol. It also presents recent trends in privacy-preserving biometric identification that aim at making it usable in real-life applications. <s> BIB007 </s> A Survey on Multimodal Biometrics and the Protection of Their Templates <s> Security and Privacy Issues <s> The iris and face are among the most promising biometric traits that can accurately identify a person because their unique textures can be swiftly extracted during the recognition process. However, unimodal biometrics have limited usage since no single biometric is sufficiently robust and accurate in real-world applications. Iris and face biometric authentication often deals with non-ideal scenarios such as off-angles, reflections, expression changes, variations in posing, or blurred images. These limitations imposed by unimodal biometrics can be overcome by incorporating multimodal biometrics. Therefore, this paper presents a method that combines face and iris biometric traits with the weighted score level fusion technique to flexibly fuse the matching scores from these two modalities based on their weight availability. The dataset use for the experiment is self established dataset named Universiti Teknologi Malaysia Iris and Face Multimodal Datasets (UTMIFM), UBIRIS version 2.0 (UBIRIS v.2) and ORL face databases. The proposed framework achieve high accuracy, and had a high decidability index which significantly separate the distance between intra and inter distance. <s> BIB008
A great number of biometric characteristics are being used in various applications. The nature of each biometric trait makes it eligible for a variety of applications. Beyond, the well-known, common seven factors that underline the suitability of the data, that is universality, uniqueness, permanence, measurability, performance, acceptability, circumvention BIB002 , there are, also, other factors that should be taken into consideration, especially when biometric systems are deployed in real-world applications  BIB004 BIB001 . Computing environments present security challenges related to aspects of multimodality BIB005 while extending and facilitating the ways of accessing may cause security threats BIB003 . The system must, at the same time, behave according to a certain policy of biometrics and be properly instrumented against attacks and actions performed by non-expert users, in order to protect information, thus meeting the requirements of irreversibility and unlinkability. After overcoming engineering and technical performance issues BIB008 , the primary research question to be addressed with regards to a multibiometric system is: How does the system address privacy concerns regarding its level of provided security to the relevant application? A starting point is the idea that with improvements of security, privacy as well as systems reliability of two or more biometrics could be combined in a method that enhances the efficiency. Following this assumption, multibiometric systems not only can reduce some threats, but also can be compromised in many ways BIB007 . In that sense, the leakage of template information to unauthorized individuals becomes a serious theme. One should bear in mind, however, that the storage of multiple biometric records of a fused template of elements, extracted from different traits, under the same identity, may offer a solution to many risks, but still, this storage has to be protected BIB006 .