- ... cracked!
^{1}
- The reason is that in 1994 Peter Shor published a quantum algorithm
which can factorize big numbers and solve the ``discrete logarithm''
in an
*efficient* way (i.e., with polynomial complexity).
Although a quantum algorithm which cracks a symmetric key efficiently
has not been invented to date (at least to my knowledge), I suppose that
it will be a question of a few years until one appears.
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- ...
question.
^{2}
- Perhaps in future times we will have inherently quantum-mechanical
questions, or only need quantum information as answers.
But this results in a whole new class of
*problems*
and goes beyond this project.
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- ...
had.
^{3}
- However, already in 1961 Rolf Landauer [2] from IBM has shown
that any
classical computation can equivalently be implemented in a reversible manner.
Therefore, quantum logic in fact is a proper generalization of Boolean
logic.
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