quantum hype

[Peter Fairbrother]

Michael_Heyman at NAI.com wrote:

>> From: owner-cryptography at metzdowd.com
>> [mailto:owner-cryptography at metzdowd.com]On Behalf Of Dave Howe
>> 
>> Peter Fairbrother may well be in possession of a break for the QC hard
>> problem - his last post stated there was a way to "clone" photons with
>> high accuracy in retention of their polarization
>> [SNIP]
>> 
> Not a break at all. The physical limit for cloning is 5/6ths of the bits will
> clone true. Alice need only send 6 bits for every one bit desired to assure
> Eve has zero information. For a 256-bit key negotiation, Alice sends 1536 bits
> and hashes it down to 256 bits for the key.

I've just discovered that that won't work. Eve can get sufficient
information to make any classical error correction or entropy distillation
techniques unuseable.

See:  http://www.gap-optique.unige.ch/Publications/Pdf/9611041.pdf


You have to use QPA instead, which has far too many theoretical assumptions
for my trust.

-- 
Peter Fairbrother

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