[extropy-chat] Encryption revolution

[scerir]

Quantum information is physical and has "permanence". 
That is because there is a no-cloning (and a stronger 
no-cloning) theorem and also a no-deleting
(and a stronger no-deleting) theorem. (Deleting is 
different from erasure, which is allowed).
http://www-users.cs.york.ac.uk/~schmuel/papers/pb00.pdf
http://www.research.ibm.com/journal/rd/481/jozsa.pdf
The above theorems are connected to the possibility
of FTL signals http://arxiv.org/abs/quant-ph/0305145
and perhaps also to a possible general principle of 
conservation of quantum information.
http://arxiv.org/abs/quant-ph/0306044
Classical information is physical but has no "permanence", 
that is to say it can be cloned, deleted, and of course 
erased. 
That "permanence" of quantum information **could** be
the conceptual reason of so many difficulties to reach a 
perfect quantum cryptography.
For a general, and clean, review of the present situation:
http://arxiv.org/abs/quant-ph/0312011