4,057 research outputs found
Defeating classical bit commitments with a quantum computer
It has been recently shown by Mayers that no bit commitment scheme is secure
if the participants have unlimited computational power and technology. However
it was noticed that a secure protocol could be obtained by forcing the cheater
to perform a measurement. Similar situations had been encountered previously in
the design of Quantum Oblivious Transfer. The question is whether a classical
bit commitment could be used for this specific purpose. We demonstrate that,
surprisingly, classical unconditionally concealing bit commitments do not help.Comment: 13 pages. Supersedes quant-ph/971202
Round Optimal Secure Multiparty Computation from Minimal Assumptions
We construct a four round secure multiparty computation (MPC) protocol in the plain model that achieves security against any dishonest majority. The security of our protocol relies only on the existence of four round oblivious transfer. This culminates the long line of research on constructing round-efficient MPC from minimal assumptions (at least w.r.t. black-box simulation)
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