Cryptography in the Bounded Quantum Storage Model
Ivan B. Damgård
July 2005 |
Abstract:
We initiate the study of two-party cryptographic primitives
with unconditional security, assuming that the adversary's quantum
memory is of bounded size. We show that oblivious transfer and bit commitment
can be implemented in this model using protocols where honest parties need no
quantum memory, whereas an adversarial player needs quantum memory of size at
least in order to break the protocol, where is the number of qubits
transmitted. This is in sharp contrast to the classical bounded-memory model,
where we can only tolerate adversaries with memory of size quadratic in
honest players' memory size. Our protocols are efficient, non-interactive and
can be implemented using today's technology. On the technical side, a new
entropic uncertainty relation involving min-entropy is
established
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