Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Approximate Opacity of Cyber-Physical Systems   Opacity is an important information-flow security property in the analysis of
cyber-physical systems. It captures the plausible deniability of the system's
secret behavior in the presence of an intruder that may access the information
flow. Existing works on opacity only consider non-metric systems by assuming
that the intruder can always distinguish two different outputs precisely. In
this paper, we extend the concept of opacity to systems whose output sets are
equipped with metrics. Such systems are widely used in the modeling of many
real-world systems whose measurements are physical signals. A new concept
called approximate opacity is proposed in order to quantitatively evaluate the
security guarantee level with respect to the measurement precision of the
intruder. Then we propose a new simulation-type relation, called approximate
opacity preserving simulation relation, which characterizes how close two
systems are in terms of the satisfaction of approximate opacity. This allows us
to verify approximate opacity for large-scale, or even infinite systems, using
their abstractions. We also discuss how to construct approximate opacity
preserving symbolic models for a class of discrete-time control systems. Our
results extend the definitions and analysis techniques for opacity from
non-metric systems to metric systems.

27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom