[cryptography] Subquantum Crypto Attack
zack.weinberg at sv.cmu.edu
Fri Jul 26 12:57:25 EDT 2013
I expect Scott Aaronson would describe this paper as 100% bunk.
On Fri, Jul 26, 2013 at 12:43 PM, John Young <jya at pipeline.com> wrote:
> Has subquantum crypto attack been substantiated?
> arXiv:quant-ph/0203049v2 12 Apr 2002
> Subquantum Information and Computation
> Antony Valentini
> It is argued that immense physical resources – for nonlocal communication,
> espionage, and exponentially-fast computation – are hidden from us by
> noise, and that this noise is not fundamental but merely a property of an
> equilibrium state in which the universe happens to be at the present time.
> is suggested that ‘non-quantum’ or nonequilibrium matter might exist today
> the form of relic particles from the early universe. We describe how such
> could be detected and put to practical use. Nonequilibrium matter could be
> used to send instantaneous signals, to violate the uncertainty principle, to
> non-orthogonal quantum states without disturbing them, to eavesdrop
> on quantum key distribution, and to outpace quantum computation (solving
> NP-complete problems in polynomial time). ...
> 6 Eavesdropping on Quantum Key Distribution
> Alice and Bob want to share a secret sequence of bits that will be used as a
> key for cryptography. During distribution of the key between them, they must
> be able to detect any eavesdropping by Eve. Three protocols for quantum key
> distribution – BB84 , B92 , and E91 (or EPR)  – are known to be
> secure against classical or quantum attacks (that is, against eavesdropping
> on classical or quantum physics) . But these protocols are not secure
> a ‘subquantum’ attack . ...
> E91 is particularly interesting for it relies on the completeness of quantum
> theory – that is, on the assumption that there are no hidden ‘elements of
> Pairs of spin-1/2 particles in the singlet state are shared by Alice and
> Bob, who
> perform spin measurements along random axes. For coincident axes the same
> sequence is generated at each wing, by apparently random quantum outcomes.
> ‘The eavesdropper cannot elicit any information from the particles while in
> transit ..... because there is no information encoded there’ . But our
> Eve has
> access to information outside the domain of quantum theory. She can measure
> the particle positions while in transit, without disturbing the
> wavefunction, and
> so predict the outcomes of spin measurements at the two wings (for the
> announced axes).12 Thus Eve is able to predict the key shared by Alice and
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> cryptography at randombit.net
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