18,661 research outputs found
An Image Forensic Scheme with Robust and Fragile Watermarking for Business Documents
This paper proposes an image forensic scheme with both robust and fragile watermarking techniques for business documents. Through a dual watermarking approach, the proposed scheme can achieve image forensics objectives of (a) identification of source; (b) authentication of documents; and (c) locating the tempered areas of documents due to attacks. An example is presented to prove the concepts of the proposed scheme.
Keywords: Image Forensics, Fragile and Robust Watermarking, Business Document
Print-Scan Resilient Text Image Watermarking Based on Stroke Direction Modulation for Chinese Document Authentication
Print-scan resilient watermarking has emerged as an attractive way for document security. This paper proposes an stroke direction modulation technique for watermarking in Chinese text images. The watermark produced by the idea offers robustness to print-photocopy-scan, yet provides relatively high embedding capacity without losing the transparency. During the embedding phase, the angle of rotatable strokes are quantized to embed the bits. This requires several stages of preprocessing, including stroke generation, junction searching, rotatable stroke decision and character partition. Moreover, shuffling is applied to equalize the uneven embedding capacity. For the data detection, denoising and deskewing mechanisms are used to compensate for the distortions induced by hardcopy. Experimental results show that our technique attains high detection accuracy against distortions resulting from print-scan operations, good quality photocopies and benign attacks in accord with the future goal of soft authentication
Ubic: Bridging the gap between digital cryptography and the physical world
Advances in computing technology increasingly blur the boundary between the
digital domain and the physical world. Although the research community has
developed a large number of cryptographic primitives and has demonstrated their
usability in all-digital communication, many of them have not yet made their
way into the real world due to usability aspects. We aim to make another step
towards a tighter integration of digital cryptography into real world
interactions. We describe Ubic, a framework that allows users to bridge the gap
between digital cryptography and the physical world. Ubic relies on
head-mounted displays, like Google Glass, resource-friendly computer vision
techniques as well as mathematically sound cryptographic primitives to provide
users with better security and privacy guarantees. The framework covers key
cryptographic primitives, such as secure identification, document verification
using a novel secure physical document format, as well as content hiding. To
make a contribution of practical value, we focused on making Ubic as simple,
easily deployable, and user friendly as possible.Comment: In ESORICS 2014, volume 8712 of Lecture Notes in Computer Science,
pp. 56-75, Wroclaw, Poland, September 7-11, 2014. Springer, Berlin, German
Touchalytics: On the Applicability of Touchscreen Input as a Behavioral Biometric for Continuous Authentication
We investigate whether a classifier can continuously authenticate users based
on the way they interact with the touchscreen of a smart phone. We propose a
set of 30 behavioral touch features that can be extracted from raw touchscreen
logs and demonstrate that different users populate distinct subspaces of this
feature space. In a systematic experiment designed to test how this behavioral
pattern exhibits consistency over time, we collected touch data from users
interacting with a smart phone using basic navigation maneuvers, i.e., up-down
and left-right scrolling. We propose a classification framework that learns the
touch behavior of a user during an enrollment phase and is able to accept or
reject the current user by monitoring interaction with the touch screen. The
classifier achieves a median equal error rate of 0% for intra-session
authentication, 2%-3% for inter-session authentication and below 4% when the
authentication test was carried out one week after the enrollment phase. While
our experimental findings disqualify this method as a standalone authentication
mechanism for long-term authentication, it could be implemented as a means to
extend screen-lock time or as a part of a multi-modal biometric authentication
system.Comment: to appear at IEEE Transactions on Information Forensics & Security;
Download data from http://www.mariofrank.net/touchalytics
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