[8390] in cryptography@c2.net mail archive
Re: Fwd: from Edupage, December 22, 2000
daemon@ATHENA.MIT.EDU (Bill Stewart)
Sat Jan 6 16:06:38 2001
Message-Id: <3.0.5.32.20010104183544.009f7650@idiom.com>
Date: Thu, 04 Jan 2001 18:35:44 -0800
To: Jaap-Henk Hoepman <hoepman@cs.utwente.nl>, cryptography@c2.net
From: Bill Stewart <bill.stewart@pobox.com>
In-Reply-To: <kpu27gzr8e.fsf@utip202.cs.utwente.nl>
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At 02:42 PM 1/3/01 +0100, Jaap-Henk Hoepman wrote:
>On Tue, 02 Jan 2001 12:03:40 -0800 David Honig <honig@sprynet.com> writes:
>> At 10:27 PM 1/1/01 +0530, Udhay Shankar N wrote:
>> >Did this slip between the cracks in holiday season or has it already been
>> >discussed here ?
>>
>> Its just yet another 'secure' scheme that uses quantum theory
>> (here, discrete photons; elsewhere, entangled photons)
>> to detect or prevent leaking bits.
>>
>> More elegant than gas-pressurized, pressure-monitored 'secure' cables, but
>> the same idea.
>
>Except that eavesdropping on the quantum key distribution channel is _always_
>detected (by `laws of nature'), which is not true for these
pressure-monitored
>cables.
The theoretical difference _is_ there, but from a practical perspective,
both are so inconvenient or expensive that even the very paranoid
won't use them, and the moderately paranoid can use multiple encryption
algorithms and overly-long keys. If you suppose that quantum crypto
hardware becomes medium-cheap, people who are connecting RF-shielded
cages together over distances of a hundred meters to a hundred kilometers
(if the quantum crypto can go that far unamplified, otherwise ~2km)
may find it more practical than pressurized cable.
If you're going less than a hundred meters, stick to pressurized
cable and armed guards :-)
Thanks!
Bill
Bill Stewart, bill.stewart@pobox.com
PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639
