Re: *Quantum Computing* expert Bill Munro

From: Bill Unruh (unruh@string.physics.ubc.ca)
Date: 04/06/03 

From: unruh@string.physics.ubc.ca (Bill Unruh)
Date: 6 Apr 2003 15:37:46 GMT

jsavard@ecn.ab.ca () writes:

]... and his colleague Keith Harrison were billed as encryption experts in
]a recent New Scientist item which I just saw today.

]In any event, these researchers called on scientists around the world to
]develop ciphers resistant to attack by quantum computers.

I did not read the article, but it sounds a bit weird.
a)Quantum computers are not here any time soon.
b) Quantum algorithms are still rather rare (fourier transform seems
still to be the only one that has been found to be useful and offereinf
an exponential speedup).

...
]Essentially, of course, as readers of my posts and website will no doubt
]realize, I would have expressed _extreme_ pessimism concerning the
]possibility of developing *public-key ciphers* that would be resistant to
]the advent of powerful quantum computers, since I am even untrustful of
]their security absent that development, since advances in mathematics
]could very easily vitiate pretty well all public-key ciphers.

Advances in mathematics can always destroy cyphers-- public or private
key. Quantum computers will not help in destroying them Unless
mathematical advances are found which make them susceptible to the very
peculiar strengths of Q Computers. Q Computers are NOT "very powerful"
except on a very limited class of problems. They will always be far less
powerful than classical computers on an operation cycle basis (error
correction is horrendously expensive for one thing), and it is only on a
small set of problems where the peculiarities of the Q Comp would be
useful.

....

Relevant Pages

  • Re: Next generation COBOL?
    ... Immediate problems aside, what COULD quantum computers potentially do for us better than conventional computers? ... algorithms which do not deal with QuBits. ... A problem not shared by programming languages. ...
    (comp.lang.cobol)
  • Rasetti: Quantum Computers based on TQFT
    ... QC can solve problems which are not in P in polynomial time. ... So the idea is that there may be more types of quantum computers than ... in as much we want to regard analog computers as computers when it ...
    (sci.physics.research)
  • Re: Rasetti: Quantum Computers based on TQFT
    ... > new and more powerful types of quantum computers. ... > polynomials is not in P. ... Analog computers tend not to work on hard problems, or when they do, ...
    (sci.physics.research)
  • Re: Incompleteness vs. Mechanical Reasoning
    ... perfectly possible future computers have free will in this sense. ... to assert that a computer's future action (e.g. will it halt or not ... NAFL, in which I have formulated my definition of free will. ... are quantum computers as defined via the NAFL model of computation ...
    (sci.logic)
  • Re: Quantum Computer vs. crypto
    ... What computers can do is described by a branch of mathematics ... computers can do, you'll need to study quantum computational theory. ... if we see quantum computers within ten years, you'll ...
    (sci.crypt)