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Henniger, Olaf; Damer, Naser; Braun, Andreas

Opportunities for Biometric Technologies in Smart Environments


Braun, Andreas (Ed.) et al.: Ambient Intelligence : 13th European Conference, AmI 2017. Springer, 2017. (Lecture Notes in Computer Science (LNCS) 10217), pp. 175-182

European Conference on Ambient Intelligence (AmI) <13, 2017, Malaga, Spain>

Smart environments describe spaces that are equipped with sensors, computing facilities and output systems that aim at providing their inhabitants with targeted services and supporting them in their tasks. Increasingly these are faced with challenges in differentiating multiple users and secure authentication. This paper outlines how biometric technologies can be applied in smart environments to overcome these challenges. We give an introduction to these domains and show various applications that can benefit from the combination of biometrics and smart environments.

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Guest, Richard Matthew; Hurtado, Oscar Miguel; Henniger, Olaf

An Assessment of Methods for Image Recreation from Signature Time-series Data


IET Biometrics, Vol.3 (2014), 3, pp. 159-166. Available online: 30 September 2013

Human signatures are widely used for biometric authentication. For automatic on-line signature verification, rather than storing an image of the completed signature, data is represented in the form of a time-series of pen position and status information allowing the extraction of temporal-based features. For visualization purposes, signature images need to be recreated from time-series data. In this paper we investigate the accuracy and verification performance of a series of interpolation methods for recreating a signature image from time-series data contained in two ISO/IEC data storage formats. Our experiments investigate dynamic data stored at various sample rates and signature images recreated at differing resolutions. Our study indicates possible best practice in terms of image recreation method, recreated image resolution, and temporal sample rate and assesses the effect of on the accuracy of reconstructed signature data.

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Butt, Moazzam; Henniger, Olaf; Nouak, Alexander; Kuijper, Arjan

Privacy Protection of Biometric Templates


Stephanidis, Constantine (Ed.): HCI International 2014 - Posters' Extended Abstracts. Proceedings Part I : HCI International 2014. Berlin, Heidelberg, New York: Springer, 2014. (Communications in Computer and Information Science (CCIS) 434), pp. 153-158

International Conference on Human-Computer Interaction (HCII) <16, 2014, Heraklion, Crete, Greece>

Although many biometric characteristics are not secrets, biometric reference data (also known as biometric templates) need to be stored securely and to be protected against unauthorized use. For this purpose, biometric template protection techniques have been developed that do not only prevent privacy leakage and provide confidentiality of the stored biometric templates, but address also problems like identity theft and cross-matching of biometric templates stored in different systems. This paper describes the security and privacy risks associated with storing biometric data and highlights the necessity of using biometric template protection as a potential remedy to these risks. Privacy considerations are discussed with respect to using fingerprint verification for access control to a public outdoor swimming pool.

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Plaza Muñoz, Sergio; Henniger, Olaf (Betreuer)

Security in Smart Grids -- A Demonstrator for the Application of Homomorphic Encryption


Mondragón, Univ, Bachelor Thesis, 2014

New homomorphic encryption methods allow carrying out calculations on encrypted data such that the results after decrypting agree with the results of the corresponding calculations on the unencrypted data. In this way, for instance, consumption data in smart grids, which contains personally identifiable and, therefore, confidential information, can be aggregated without the data being present in clear. The first open source implementations of homomorphic encryption methods are already available, and the goal of the project is to create a homomorphic encryption demonstrator.

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Henniger, Olaf; Muramatsu, Daigo; Matsumoto, Takashi; Yoshimura, Isao; Yoshimura, Mitsu

Signature Recognition, Overview


Li, Stan Z. (Ed.) et al.: Encyclopedia of Biometrics. Berlin, Heidelberg, New York: Springer, 2014, 4 p.

A signature is a handwritten representation of a person's name. Writing a signature is the established method for authentication and for expressing deliberate decisions of the signer in many areas of life, such as banking or the conclusion of legal contracts. A closely related concept is a handwritten personal sign depicting something else than a person's name. As compared to text-independent writer recognition methods, signature/sign recognition goes with shorter handwriting probes but requires writing the same name or personal sign every time. Handwritten signatures and personal signs belong to the behavioral biometric characteristics as the person must become active for signing. Regarding the automated recognition of handwritten signatures, there is a distinction between online signatures and offline signatures.

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Henniger, Olaf; Guest, Richard; Miguel-Hurtado, Oscar; Kaplan, Christiane

Signature/Sign Time Series Data - Standardization


Li, Stan Z. (Ed.) et al.: Encyclopedia of Biometrics. Berlin, Heidelberg, New York: Springer, 2014, 7 p.

The International Standard ISO/IEC 19794-7 specifies data interchange formats for online signature data in the form of multidimensional time series representing the signature dynamics. ISO/IEC 19794-7 specifies the following data formats for online signature time series data: a full format applicable in a wide range of application areas where handwritten online signatures or signs are involved, a compression format, a compact format, and an XML-based format. These formats support interoperability and data interchange among the subsystems of open online signature recognition systems.

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Guest, Richard; Henniger, Olaf

Assessment of the Quality of Handwritten Signatures Based on Multiple Correlations


Ortega-Garcia, Javier (Ed.) et al.: 2013 International Conference on Biometrics (ICB). New York: IEEE Press, 2013, 6 p.

IAPR International Conference on Biometrics (ICB) <6, 2013, Madrid, Spain>

Assuring the quality of individual biometric samples is important for maintaining the discriminatory power of biometric recognition systems as biometric data of low-quality are likely to be mismatched. This paper presents an investigation into the assessment of the quality of handwritten signatures, predicting the performance or 'utility' of individual signature samples in automated biometric recognition. The prediction of utility is based on multiple correlations with static and dynamic signature features. First, the utility of handwritten signature samples from publicly available databases is assessed by comparing them with each other using commercial automatic signature verification engines. The samples are classified into four quality bins (excellent, adequate, marginal, and unacceptable quality) with totally ordered bin boundaries. Then, the correlation of multiple static and dynamic signature features with utility is analysed to find features that can be used for predicting the utility of samples. Our results show that it is possible to predict the utility of handwritten signature samples using a multi-feature vector.

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Henniger, Olaf; Nikolov, Dimitar

Extending EMV Payment Smart Cards with Biometric On-Card Verification


Fischer-Hübner, Simone (Ed.) et al.: Policies and Research in Identity Management : Third IFIP WG 11.6 Working Conference, IDMAN 2013. Proceedings. Berlin, Heidelberg, New York: Springer, 2013. (IFIP Advances in Information and Communication Technology 396), pp. 121-130

IFIP WG 11.6 Working Conference on Policies & Research in Identity Management (IDMAN) <3, 2013, London, UK>

Nowadays, many bank cards are smart cards (i.e. integrated-circuit cards) based on the EMV specifications for payment systems. This paper specifies how biometric on-card verification can be integrated into EMV debit and credit cards in a backwards-compatible way. The biometric verification does not change the EMV transaction flow outside the cardholder-verification step. The proposed payment system has been prototyped using Java cards and an applet for handwritten signature on-card verification.

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Martin, José Francisco Ayudarte; Henniger, Olaf (Betreuer)

Remote Biometric Authentication via Internet


Mondragon, Univ., Bachelor Thesis, 2013

This document describes the security measures needed for the implementation of a biometric verification system via Internet. It analyzes the different parts of the architecture that are susceptible to be attacked by a malicious outsider and how these parts can be protected. A prototype of the solution is designed and developed. Finally, the prototype is analyzed to see if the project was successful.

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Henniger, Olaf

Biometrie auf Smartcards


Waldmann, Ulrich (Ed.): 22. SIT-SmartCard Workshop : Tagungsband 2012. Stuttgart: Fraunhofer Verlag, 2012, pp. 156-158

SIT-SmartCard Workshop <22, 2012, Darmstadt, Germany>

Starke Authentisierung erfordert den Einsatz von Hardware-Sicherheitstoken, z. B. in der Form von kontaktbehafteten oder kontaktlosen Smartcards, zusammen mit weiteren Authentisierungsfaktoren. Biometrie, d. h. die automatisierte Erkennung von Personen an Hand von biologischen Merkmalen oder Verhaltensmerkmalen, ist eine vielversprechende Technologie für die Authentisierung von Personen. Dieser Beitrag gibt einen Überblick über einige Einsatzmöglichkeiten und Anwendungen von Smartcards in Verbindung mit Biometrie und über Stärken und Schwächen biometrischer Verfahren.

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Henniger, Olaf; Scheuermann, Dirk; Schneider, Björn; Struif, Bruno; Waldmann, Ulrich; Ulrich, Reiner; Franke, Katrin; Schneider, Jan; Daum, Henning

Zurechenbarkeit von Aktionen in virtuellen Welten: BMBF-Projekt ZAVIR: Schlussbericht


Darmstadt, 2004

Neben Vertraulichkeit sind Integrität, Authentizität und Nichtabstreitbarkeit wichtige Anforderungen an die Sicherheit von Informationstechnik. Wenn Benutzer über Kommunikationsnetze Nachrichten austauschen, wollen sie i. allg., dass diese nicht von Unbefugten mitgehört oder gelesen werden können (Vertraulichkeit), sie wollen feststellen, ob Informationen unverändert beim Empfänger ankommen (Integrität), und sie wollen wissen, wer der Urheber von Informationen ist, ohne dass sich jemand anders als Urheber ausgeben kann (Authentizität) und ohne dass der Urheber seine Urheberschaft abstreiten kann (Nichtabstreitbarkeit). Diese Anforderungen gewinnen im Zusammenhang mit "elektronischem Handel" (E-Commerce) und "elektronischer Verwaltung" (E-Government) an Bedeutung, da sich die Kommunikationspartner nicht notwendigerweise kennen und vertrauen. Mit Hilfe elektronischer Signaturen ist die Erfüllung von Sicherheitsanforderungen nach Integrität, Authentizität und Nichtabstreitbarkeit theoretisch möglich. In der Praxis reicht das Vertrauen in elektronische Signaturen jedoch gegenwärtig nicht aus, um sie für Geschäfte, bei denen es um höhere Werte geht, einzusetzen. Höherwertige elektronische Bestellungen oder Transaktionen werden heute kaum ohne zusätzliche Bestätigung z. B. per Telefon oder Fax ausgeführt. Eine Ursache ist, dass die bei der Erzeugung elektronischer Signaturen übliche, wissensbasierte Benutzerauthentisierung nur einen schwachen Nachweis der tatsächlichen Urheberschaft und des Rechtsbindungswillens bietet. Wissensbasierte Authentisierungsdaten (PIN oder Passwort) können in die Hände unberechtigter Personen gelangen. Nach der Präsentation gültiger Authentisierungsdaten werden elektronische Signaturen erzeugt, gleichgültig, ob die Authentisierungsdaten von einer berechtigten oder einer unberechtigten Person präsentiert wurden. Eine weitere Ursache für die gegenwärtig mangelnde Vertrauenswürdigkeit elektronischer Signaturen ist, dass bei der Erzeugung elektronischer Signaturen nicht immer tatsächlich nur das signiert wird, was der Benutzer signieren will. Zum einen laufen die Signaturanwendung einschließlich der Dokumentenpräsentationskomponente oftmals auf PCs unter einem Betriebssystem ab, auf dem Manipulationen nicht ausgeschlossen werden können. Zum anderen können zu signierende Dokumente in Dateiformaten vorliegen, die nicht sichtbare Informationen enthalten und die auf verschiedenen Rechnern auf unterschiedliche Weise dargestellt werden können. Zur Lösung der genannten Probleme wurden im Rahmen des Projektes ein vertrauenswürdiges, vor unberechtigten Manipulationen geschütztes Kartenterminal für Signaturkarten (Trusted Signature Terminal, TST) konzipiert und prototypisch realisiert und Beiträge zur Nutzbarmachung biometrischer Verfahren wie Fingerabdruckerkennung und On-line-Unterschriftenerkennung für die Benutzerauthentisierung auf Signaturkarten geleistet.