7,451 research outputs found
Quantum Data Hiding
We expand on our work on Quantum Data Hiding -- hiding classical data among
parties who are restricted to performing only local quantum operations and
classical communication (LOCC). We review our scheme that hides one bit between
two parties using Bell states, and we derive upper and lower bounds on the
secrecy of the hiding scheme. We provide an explicit bound showing that
multiple bits can be hidden bitwise with our scheme. We give a preparation of
the hiding states as an efficient quantum computation that uses at most one
ebit of entanglement. A candidate data hiding scheme that does not use
entanglement is presented. We show how our scheme for quantum data hiding can
be used in a conditionally secure quantum bit commitment scheme.Comment: 19 pages, IEEE style, 8 figures, submitted to IEEE Transactions on
Information Theor
Quantum data hiding in the presence of noise
When classical or quantum information is broadcast to separate receivers,
there exist codes that encrypt the encoded data such that the receivers cannot
recover it when performing local operations and classical communication, but
they can decode reliably if they bring their systems together and perform a
collective measurement. This phenomenon is known as quantum data hiding and
hitherto has been studied under the assumption that noise does not affect the
encoded systems. With the aim of applying the quantum data hiding effect in
practical scenarios, here we define the data-hiding capacity for hiding
classical information using a quantum channel. Using this notion, we establish
a regularized upper bound on the data hiding capacity of any quantum broadcast
channel, and we prove that coherent-state encodings have a strong limitation on
their data hiding rates. We then prove a lower bound on the data hiding
capacity of channels that map the maximally mixed state to the maximally mixed
state (we call these channels "mictodiactic"---they can be seen as a
generalization of unital channels when the input and output spaces are not
necessarily isomorphic) and argue how to extend this bound to generic channels
and to more than two receivers.Comment: 12 pages, accepted for publication in IEEE Transactions on
Information Theor
Quantum data hiding with spontaneous parameter down-conversion
Here we analyze the practical implication of the existing quantum data hiding
protocol with Bell states produced with optical downconverter. We show that the
uncertainty for the producing of the Bell states with spontaneous parameter
down-conversion should be taken into account, because it will cause serious
trouble to the hider encoding procedure. A set of extended Bell states and a
generalized Bell states analyzer are proposed to describe and analyze the
possible states of two photons distributing in two paths. Then we present a
method to integrate the above uncertainty of Bell states preparation into the
dating hiding procedure, when we encode the secret with the set of extended
Bell states. These modifications greatly simplify the hider's encoding
operations, and thus paves the way for the implementation of quantum data
hiding with present-day quantum optics.Comment: 4 pages, 1 figure, adding some analyse for security proof, to be
appear in Phys. Rev.
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