652 research outputs found
To Obtain or not to Obtain CSI in the Presence of Hybrid Adversary
We consider the wiretap channel model under the presence of a hybrid, half
duplex adversary that is capable of either jamming or eavesdropping at a given
time. We analyzed the achievable rates under a variety of scenarios involving
different methods for obtaining transmitter CSI. Each method provides a
different grade of information, not only to the transmitter on the main
channel, but also to the adversary on all channels. Our analysis shows that
main CSI is more valuable for the adversary than the jamming CSI in both
delay-limited and ergodic scenarios. Similarly, in certain cases under the
ergodic scenario, interestingly, no CSI may lead to higher achievable secrecy
rates than with CSI.Comment: 8 pages, 3 figure
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
Duality of privacy amplification against quantum adversaries and data compression with quantum side information
We show that the tasks of privacy amplification against quantum adversaries
and data compression with quantum side information are dual in the sense that
the ability to perform one implies the ability to perform the other. These are
two of the most important primitives in classical information theory, and are
shown to be connected by complementarity and the uncertainty principle in the
quantum setting. Applications include a new uncertainty principle formulated in
terms of smooth min- and max-entropies, as well as new conditions for
approximate quantum error correction.Comment: v2: Includes a derivation of an entropic uncertainty principle for
smooth min- and max-entropies. Discussion of the
Holevo-Schumacher-Westmoreland theorem remove
Threshold Ring Signatures: New Definitions and Post-Quantum Security
A -out-of- threshold ring signature allows parties to jointly and anonymously compute a signature on behalf on public keys, selected in an arbitrary manner among the set of all public keys registered in the system.
Existing definitions for -out-of- threshold ring signatures guarantee security only when the public keys are honestly generated, and many even restrict the ability of the adversary to actively participate in the computation of the signatures.
Such definitions do not capture the open settings envisioned for threshold ring signatures, where parties can independently add themselves to the system, and join other parties for the computation of the signature.
Furthermore, known constructions of threshold ring signatures are not provably secure in the post-quantum setting, either because they are based on non-post quantum secure problems (e.g. Discrete Log, RSA), or because they rely on transformations such as Fiat-Shamir, that are not always secure in the quantum random oracle model (QROM).
In this paper, we provide the first definition of -out-of- threshold ring signatures against {\em active} adversaries who can participate in the system and arbitrarily deviate from the prescribed procedures. Second, we present a post-quantum secure realization based on {\em any} (post-quantum secure) trapdoor commitment, which we prove secure in the QROM.
Our construction is black-box and it can be instantiated with any trapdoor commitment, thus allowing the use of a variety of hardness assumptions
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