Re: Cryptography

James Rogers (
Tue, 24 Dec 1996 12:27:46 -0800

At 10:57 AM 12/24/96 -0800, you wrote:
> >Apart from the possible difficulty of making a kilobit

> >quantum computer, I hadn't heard that they would be useful

> >for cracking symmetric ciphers. They could factor numbers

> >happily, thus bye-bye RSA and Blum-Blum-Shup; can they do

> >tons of IDEA or RC4 attempts as well?
>If a Quantum Computers is ever made then the only Cryptography that would
>still work would be one time pads and Quantum Cryptography. One time pads
>were used in the first world war, but they are very hard to implement because
>it's difficult to distribute pads securely to everyone who needs one. Quantum
>Cryptography has already been used in the real world and not just in the lab,
>the only reason it isn't more popular is that we already have public key
>cryptography and nobody yet has a Quantum Computers. I should add that if a
>Quantum Computer is made then the world will change so fast and so radically
>that the fact that you can no longer use PGP safely would be the last thing
>you'd be worrying about.

What about encryption algorithms specifically designed to be operated on
quantum computers? The same properties that make quantum computers so adept
at cracking codes could also be used to make encryption that much stronger.
Halting Problem?

-James Rogers