1,668 research outputs found
Resilient Distributed Optimization Algorithms for Resource Allocation
Distributed algorithms provide flexibility over centralized algorithms for
resource allocation problems, e.g., cyber-physical systems. However, the
distributed nature of these algorithms often makes the systems susceptible to
man-in-the-middle attacks, especially when messages are transmitted between
price-taking agents and a central coordinator. We propose a resilient strategy
for distributed algorithms under the framework of primal-dual distributed
optimization. We formulate a robust optimization model that accounts for
Byzantine attacks on the communication channels between agents and coordinator.
We propose a resilient primal-dual algorithm using state-of-the-art robust
statistics methods. The proposed algorithm is shown to converge to a
neighborhood of the robust optimization model, where the neighborhood's radius
is proportional to the fraction of attacked channels.Comment: 15 pages, 1 figure, accepted to CDC 201
Adversarial sample generation and training using geometric masks for accurate and resilient license plate character recognition
Reading dirty license plates accurately in moving vehicles is challenging for
automatic license plate recognition systems. Moreover, license plates are often
intentionally tampered with a malicious intent to avoid police apprehension.
Usually, such groups and individuals know how to fool the existing recognition
systems by making minor unnoticeable plate changes. Designing and developing
deep learning methods resilient to such real-world 'attack' practices remains
an active research problem. As a solution, this work develops a resilient
method to recognize license plate characters. Extracting 1057 character images
from 160 Nepalese vehicles, as the first step, we trained several standard deep
convolutional neural networks to obtain 99.5% character classification
accuracy. On adversarial images generated to simulate malicious tampering,
however, our model's accuracy dropped to 25%. Next, we enriched our dataset by
generating and adding geometrically masked images, retrained our models, and
investigated the models' predictions. The proposed approach of training with
generated adversarial images helped our adversarial attack-aware license plate
character recognition (AA-LPCR) model achieves an accuracy of 99.7%. This
near-perfect accuracy demonstrates that the proposed idea of random geometric
masking is highly effective for improving the accuracy of license plate
recognition models. Furthermore, by performing interpretability studies to
understand why our models work, we identify and highlight attack-prone regions
in the input character images. In sum, although Nepal's embossed license plate
detection systems are vulnerable to malicious attacks, our findings suggest
that these systems can be upgraded to close to 100% resilience
Building Confidential and Efficient Query Services in the Cloud with RASP Data Perturbation
With the wide deployment of public cloud computing infrastructures, using
clouds to host data query services has become an appealing solution for the
advantages on scalability and cost-saving. However, some data might be
sensitive that the data owner does not want to move to the cloud unless the
data confidentiality and query privacy are guaranteed. On the other hand, a
secured query service should still provide efficient query processing and
significantly reduce the in-house workload to fully realize the benefits of
cloud computing. We propose the RASP data perturbation method to provide secure
and efficient range query and kNN query services for protected data in the
cloud. The RASP data perturbation method combines order preserving encryption,
dimensionality expansion, random noise injection, and random projection, to
provide strong resilience to attacks on the perturbed data and queries. It also
preserves multidimensional ranges, which allows existing indexing techniques to
be applied to speedup range query processing. The kNN-R algorithm is designed
to work with the RASP range query algorithm to process the kNN queries. We have
carefully analyzed the attacks on data and queries under a precisely defined
threat model and realistic security assumptions. Extensive experiments have
been conducted to show the advantages of this approach on efficiency and
security.Comment: 18 pages, to appear in IEEE TKDE, accepted in December 201
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
CALLOC: Curriculum Adversarial Learning for Secure and Robust Indoor Localization
Indoor localization has become increasingly vital for many applications from
tracking assets to delivering personalized services. Yet, achieving pinpoint
accuracy remains a challenge due to variations across indoor environments and
devices used to assist with localization. Another emerging challenge is
adversarial attacks on indoor localization systems that not only threaten
service integrity but also reduce localization accuracy. To combat these
challenges, we introduce CALLOC, a novel framework designed to resist
adversarial attacks and variations across indoor environments and devices that
reduce system accuracy and reliability. CALLOC employs a novel adaptive
curriculum learning approach with a domain specific lightweight scaled-dot
product attention neural network, tailored for adversarial and variation
resilience in practical use cases with resource constrained mobile devices.
Experimental evaluations demonstrate that CALLOC can achieve improvements of up
to 6.03x in mean error and 4.6x in worst-case error against state-of-the-art
indoor localization frameworks, across diverse building floorplans, mobile
devices, and adversarial attacks scenarios
- …