[extropy-chat] Encryption revolution

[Eugen Leitl]

On Sun, Dec 07, 2003 at 04:18:42PM -0500, John K Clark wrote:

> Apparently quite a bit of money is going into developing quantum encryption,

That's because it's a brand new field in crypto snake oil.

> I'm a little surprised because public key encryption is much easier to use
> and seems safe enough.  The only conclusion I can come up with is that

Entangled photons are just used to distribute a shared secret (symmetric
session key). It's supposed to be a tamper-proof way to rekey remotely. 
It's not sooo tamperproof, but definitely better than to send your session 
keys via snail mail.

There have been excessive discussion of this technology on diverse
lists, cryptography@ included. Several attacks have been proposed.
(I haven't been keeping track of details, because it's boring).

> somebody with money thinks a practical quantum computer will soon become a

Nope. It's just about milking gullible fools. Application niches
targeted are securing financial crypto fiber lines and ground-LEO
sat rekeying (they don't yet work in free atmosphere over this range,
but eventually will). Tamper detection is definitely a boon here.

> reality. If that happens then quantum encryption will be the only way to
> keep a secret.

Nope, QM is only useful for number factoring, and despite encouraging
movements in solid state entanglement we're as far removed from QM
as ever. Nevermind the issue of how this scales to high qubit numbers
(it doesn't).

-- Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07078, 11.61144            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
http://moleculardevices.org         http://nanomachines.net
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20031207/827d5b5c/attachment.bin>