Media encryption for still visual data : an analysis of selected techniques for natural images and fingerprint data in the spatial and wavelet domain / Dominik Engel

• VerfasserIn: Engel, Dominik
• Place / Publishing House: 2008
• Year of Publication: 2008
• Language: English
• Classification: 54.74 - Maschinelles Sehen; 54.38 - Computersicherheit
• Physical Description: XXI, 214 S.; Ill., graph. Darst.
• Notes: Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers; http://wavelab.at/papers/Engel08b.pdf

ger: We propose, discuss and evaluate a range of techniques for media encryption for still visual data. Two classes of visual data are used in the investigation: natural still images and fingerprint data. In terms of representational format, we focus on scalable representations of the source data.<br />We propose different security techniques for visual data coded with the wavelet-based scalable JPEG2000 standard, some of which are exclusive to JPEG2000, whereas others are more generally applicable.<br />We discuss techniques for format-compliant JPEG2000 encryption and propose a bitstream-oriented packet header protection scheme, that can overcome security flaws present in virtually all existing format-compliant encryption scheme for JPEG2000. We then turn to compression-integrated encryption of wavelet-coded visual data. We propose and evaluate the utility of two classes of key-dependent transform domains for encryption: parameterized wavelet filters and wavelet packets. We show, that the former are insecure, because they are vulnerable to a symbolic transform attack, whereas the latter can achieve high levels of security while retaining competitive compression performance, especially in the case of anisotropic wavelet packets.<br />A major focus of this thesis is the analysis and evaluation of the proposed schemes, but also of existing media encryption schemes. One area where the severity of the compromise in security that is introduced by design mistakes is especially evident is the protection of biometric data, where revocation is usually impossible. In this context we analyze an image-based selective encryption scheme, that has recently been proposed in the context of fingerprint encryption. We discuss severe design mistakes and present an efficient attack.