768 research outputs found
Statistical Watermarking for Networked Control Systems
Watermarking can detect sensor attacks in control systems by injecting a
private signal into the control, whereby attacks are identified by checking the
statistics of the sensor measurements and private signal. However, past
approaches assume full state measurements or a centralized controller, which is
not found in networked LTI systems with subcontrollers. Since generally the
entire system is neither controllable nor observable by a single subcontroller,
communication of sensor measurements is required to ensure closed-loop
stability. The possibility of attacking the communication channel has not been
explicitly considered by previous watermarking schemes, and requires a new
design. In this paper, we derive a statistical watermarking test that can
detect both sensor and communication attacks. A unique (compared to the
non-networked case) aspect of the implementing this test is the state-feedback
controller must be designed so that the closed-loop system is controllable by
each sub-controller, and we provide two approaches to design such a controller
using Heymann's lemma and a multi-input generalization of Heymann's lemma. The
usefulness of our approach is demonstrated with a simulation of detecting
attacks in a platoon of autonomous vehicles. Our test allows each vehicle to
independently detect attacks on both the communication channel between vehicles
and on the sensor measurements
Exploratory study to explore the role of ICT in the process of knowledge management in an Indian business environment
In the 21st century and the emergence of a digital economy, knowledge and the knowledge base economy are rapidly growing. To effectively be able to understand the processes involved in the creating, managing and sharing of knowledge management in the business environment is critical to the success of an organization. This study builds on the previous research of the authors on the enablers of knowledge management by identifying the relationship between the enablers of knowledge management and the role played by information communication technologies (ICT) and ICT infrastructure in a business setting. This paper provides the findings of a survey collected from the four major Indian cities (Chennai, Coimbatore, Madurai and Villupuram) regarding their views and opinions about the enablers of knowledge management in business setting. A total of 80 organizations participated in the study with 100 participants in each city. The results show that ICT and ICT infrastructure can play a critical role in the creating, managing and sharing of knowledge in an Indian business environment
Learning-based attacks in cyber-physical systems
We introduce the problem of learning-based attacks in a simple abstraction of
cyber-physical systems---the case of a discrete-time, linear, time-invariant
plant that may be subject to an attack that overrides the sensor readings and
the controller actions. The attacker attempts to learn the dynamics of the
plant and subsequently override the controller's actuation signal, to destroy
the plant without being detected. The attacker can feed fictitious sensor
readings to the controller using its estimate of the plant dynamics and mimic
the legitimate plant operation. The controller, on the other hand, is
constantly on the lookout for an attack; once the controller detects an attack,
it immediately shuts the plant off. In the case of scalar plants, we derive an
upper bound on the attacker's deception probability for any measurable control
policy when the attacker uses an arbitrary learning algorithm to estimate the
system dynamics. We then derive lower bounds for the attacker's deception
probability for both scalar and vector plants by assuming a specific
authentication test that inspects the empirical variance of the system
disturbance. We also show how the controller can improve the security of the
system by superimposing a carefully crafted privacy-enhancing signal on top of
the "nominal control policy." Finally, for nonlinear scalar dynamics that
belong to the Reproducing Kernel Hilbert Space (RKHS), we investigate the
performance of attacks based on nonlinear Gaussian-processes (GP) learning
algorithms
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