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Auflistung nach Autor:in "Henniger, Olaf"

1 - 7 von 7
  • Konferenzbeitrag
    Biometrische Benutzerauthentisierung auf Smartcards mittels handschriftlicher Unterschriften
    (INFORMATIK 2003 - Mit Sicherheit Informatik, Schwerpunkt "Sicherheit - Schutz und Zuverlässigkeit", 2003) Henniger, Olaf; Franke, Katrin
    Dieser Beitrag beschreibt ein biometrisches Verfahren zur Benutzerauthentisierung auf einer Smartcard. Die biometrischen Daten, die betrachtet werden, sind On-line-Unterschriften, d. h. handgeschriebene Unterschriften, die mit Hilfe eines graphischen Tabletts und/oder eines Spezialstifts aufgenommen werden.
  • Konferenzbeitrag
    Minutiae Template Conformance and Interoperability Issues
    (BIOSIG 2007: biometrics and electronic signatures, 2007) Henniger, Olaf; Scheuermann, Dirk
    Minutiae features extracted from finger images are widely used for automated fingerprint recognition. The conformance of minutiae templates to standardised data interchange formats and the interoperability of minutiae extraction and comparison subsystems from multiple suppliers are important to prevent proprietary lock-in. Based on the work performed within the European research project on minutiae template interoperability testing, this paper summarises conformance and interoperability issues that have arisen and proposes solutions.
  • Konferenzbeitrag
    On biometric key generation from handwritten signatures
    (BIOSIG 2011 – Proceedings of the Biometrics Special Interest Group, 2011) Scheuermann, Dirk; Wolfgruber, Bastian; Henniger, Olaf
    This paper investigates the extraction of a reproducible bit string referred to as biometric key from biometric data. This is difficult due to the natural variability of biometric data. If the biometric-key generation process were sufficiently resistant against attacks, a biometric key may be used e.g. as basis for the generation of application-specific user passwords. Handwritten signatures or handwritten signs have been chosen because of their high level of user acceptance and because the exchange of compromised keys is possible by using other phrases to write. The experimental results show an insufficient reproducibility of the biometric keys if no auxiliary data is used for smoothing out the natural variability of the presented data.
  • Konferenzbeitrag
    On the assessment of face image quality based on handcrafted features
    (BIOSIG 2020 - Proceedings of the 19th International Conference of the Biometrics Special Interest Group, 2020) Henniger, Olaf; Fu, Biying; Chen, Cong
    This paper studies the assessment of the quality of face images, predicting the utility of face images for automated recognition. The utility of frontal face images from a publicly available dataset was assessed by comparing them with each other using commercial off-the-shelf face recognition systems. Multiple face image features delineating face symmetry and characteristics of the capture process were analysed to find features predictive of utility. The selected features were used to build system-specific and generic random forest classifiers.
  • Konferenzbeitrag
    OpenPGP-Karten mit biometrischer Benutzerauthentisierung
    (SICHERHEIT 2008 – Sicherheit, Schutz und Zuverlässigkeit. Beiträge der 4. Jahrestagung des Fachbereichs Sicherheit der Gesellschaft für Informatik e.V. (GI), 2008) Trukenmüller, Jan; Henniger, Olaf
    OpenPGP-Karten sind Smartcards, die private OpenPGP-Schlüs- sel sicher speichern und Entschlüsselungs- und Signierfunktionen bereitstellen. Der Benutzer einer OpenPGP-Karte muss sich gegenüber der Karte authentisieren. Dieser Beitrag beschreibt die prototypische Implementierung von OpenPGP-Karten mit bio- metrischem On-Card-Matching. Außerdem wird die Integration der Komponenten zur Erfassung und Verarbeitung biometrischer Daten in eine OpenPGP-basierte E-Mail-Anwendung beschrieben. Als Methoden zur Benutzerauthentisierung werden neben Passwörtern Fingerabdrücke und handgeschriebene Unterschriften unterstützt.
  • Konferenzbeitrag
    The relative contributions of facial parts qualities to the face image utility
    (BIOSIG 2021 - Proceedings of the 20th International Conference of the Biometrics Special Interest Group, 2021) Fu, Biying; Chen, Cong; Henniger, Olaf; Damer, Naser
    Face image quality assessment predicts the utility of a face image for automated face recognition. A high-quality face image can achieve good performance for the identification or verification task. Some recent face image quality assessment algorithms are established on deep-learningbased approaches, which rely on face embeddings of aligned face images. Such face embeddings fuse complex information into a single feature vector and are, therefore, challenging to disentangle. The semantic context however can provide better interpretable insights into neural-network decisions. We investigate the effects of face subregions (semantic contexts) and link the general image quality of face subregions with face image utility. The evaluation is performed on two difficult largescale datasets (LFW and VGGFace2) with three face recognition solutions (FaceNet, SphereFace, and ArcFace). In total, we applied four face image quality assessment methods and one general image quality assessment method on four face subregions (eyes, mouth, nose, and tightly cropped face region) and the aligned faces. In addition, the effect of fusion of different face subregions was investigated to increase the robustness of the outcomes
  • Konferenzbeitrag
    Supplemental biometric user authentication for digital-signature smart cards
    (BIOSIG 2009: biometrics and electronic signatures, 2009) Henniger, Olaf; Waldmann, Ulrich
    This paper specifies how biometric verification methods can be applied in addition to PIN verification on digital-signature smart cards in compliance with established smart-card standards. After successful PIN verification, multiple digital signatures can be created; each signature creation, however, is preceded by biometric verification.