8 research outputs found
Gaussian Secure Source Coding and Wyner's Common Information
We study secure source-coding with causal disclosure, under the Gaussian
distribution. The optimality of Gaussian auxiliary random variables is shown in
various scenarios. We explicitly characterize the tradeoff between the rates of
communication and secret key. This tradeoff is the result of a mutual
information optimization under Markov constraints. As a corollary, we deduce a
general formula for Wyner's Common Information in the Gaussian setting.Comment: ISIT 2015, 5 pages, uses IEEEtran.cl
The CEO Problem with Secrecy Constraints
We study a lossy source coding problem with secrecy constraints in which a
remote information source should be transmitted to a single destination via
multiple agents in the presence of a passive eavesdropper. The agents observe
noisy versions of the source and independently encode and transmit their
observations to the destination via noiseless rate-limited links. The
destination should estimate the remote source based on the information received
from the agents within a certain mean distortion threshold. The eavesdropper,
with access to side information correlated to the source, is able to listen in
on one of the links from the agents to the destination in order to obtain as
much information as possible about the source. This problem can be viewed as
the so-called CEO problem with additional secrecy constraints. We establish
inner and outer bounds on the rate-distortion-equivocation region of this
problem. We also obtain the region in special cases where the bounds are tight.
Furthermore, we study the quadratic Gaussian case and provide the optimal
rate-distortion-equivocation region when the eavesdropper has no side
information and an achievable region for a more general setup with side
information at the eavesdropper.Comment: Accepted for publication in IEEE Transactions on Information
Forensics and Security, 17 pages, 4 figure
Outer Bounds on the CEO Problem with Privacy Constraints
We investigate the rate-distortion-leakage region of the Chief Executive
Officer (CEO) problem with a passive eavesdropper and privacy constraints,
considering a general distortion measure. While an inner bound directly follows
from the previous work, an outer bound is newly developed in this paper. To
derive this bound, we introduce a new lemma tailored for analyzing privacy
constraints. As a specific instance, we demonstrate that the tight bound for
discrete and Gaussian sources is obtained when the eavesdropper can only
observe the messages under logarithmic loss distortion. We further investigate
the rate-distortion-leakage region for a scenario where the eavesdropper
possesses the messages and side information under the same distortion, and
provide an outer bound for this particular case. The derived outer bound
differs from the inner bound by only a minor quantity that appears in the
constraints associated with the privacy-leakage rates, and it becomes tight
when the distortion is large.Comment: 14 pages, 4 figure
Secure and Private Distributed Source Coding with Private Keys and Decoder Side Information
The distributed source coding problem is extended by positing that noisy measurements of a remote source are the correlated random variables that should be reconstructed at another terminal. We consider a secure and private distributed lossy source coding problem with two encoders and one decoder such that (i) all terminals noncausally observe a noisy measurement of the remote source; (ii) a private key is available to each legitimate encoder and all private keys are available to the decoder; (iii) rate-limited noiseless communication links are available between each encoder and the decoder; (iv) the amount of information leakage to an eavesdropper about the correlated random variables is defined as secrecy leakage, and privacy leakage is measured with respect to the remote source; and (v) two passive attack scenarios are considered, where a strong eavesdropper can access both communication links and a weak eavesdropper can only choose one of the links to access. Inner and outer bounds on the rate regions defined under secrecy, privacy, communication, and distortion constraints are derived for both passive attack scenarios. When one or both sources should be reconstructed reliably, the rate region bounds are simplified