LXer: Quantum Cryptography

LXer · 04-22-2014, 01:10 PM

Published at LXer:

Classical cryptography provides security based on unprovenmathematical assumptions and depends on the technology available toan eavesdropper. But, these things might not be enough in the near future toguaranteecyber security. We need something thatprovides unconditional security. We need quantum cryptography.

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metaschima · 04-22-2014, 02:31 PM

Too bad quantum cryptography provides security based on unproven assumption of the existence of Quantum Cryptography.

273 · 04-22-2014, 03:26 PM

Quote:

Originally Posted by metaschima

Too bad quantum cryptography provides security based on unproven assumption of the existence of Quantum Cryptography.

May I ask when your paper is due to be published? I'd like to read it and the comments of quantum physicists.

metaschima · 04-22-2014, 05:10 PM

Found the link even tho slashdot has been slow all day:
http://tech.slashdot.org/story/14/02...ntum-after-all

273 · 04-23-2014, 12:56 AM

Quote:

Originally Posted by metaschima

Found the link even tho slashdot has been slow all day:
http://tech.slashdot.org/story/14/02...ntum-after-all

That's a quantum computer and not quantum cryptography.

metaschima · 04-23-2014, 11:34 AM

So, you're saying quantum cryptography can exist without a quantum computer ? I never heard that this was possible. I'd like to test it if it is.

273 · 04-23-2014, 11:38 AM

Quote:

Originally Posted by metaschima

So, you're saying quantum cryptography can exist without a quantum computer ? I never heard that this was possible. I'd like to test it if it is.

They have very little to do with each other apart from both being based upon phenomena related to quantum physics.

metaschima · 04-23-2014, 11:59 AM

Quote:

Well-known examples of quantum cryptography are the use of quantum communication to exchange a key securely (quantum key distribution) and the hypothetical use of quantum computers that would allow the breaking of various popular public-key encryption and signature schemes (e.g., RSA and ElGamal).

The advantage of quantum cryptography lies in the fact that it allows the completion of various cryptographic tasks that are proven or conjectured to be impossible using only classical (i.e. non-quantum) communication (see below for examples).

http://en.wikipedia.org/wiki/Quantum_cryptography

Quote:

Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key.[1]

http://en.wikipedia.org/wiki/Quantum_key_distribution

There's nothing quantum about the one-time pad. Quantum cryptography did not exist during the cold war, but the one-time pad did.

I don't see any reason to believe that:
1) Quantum cryptography is possible without special / quantum computers.
2) Quantum computers and thus cryptography actually exist.
3) If they do exist that they are any good just because Dr. Manhattan says so.

273 · 04-23-2014, 12:32 PM

They use "quantum communication" which, though not unrelated to quantum computers, does not require them.
The word "quantum" does not mean "refers to quantum computing" it is the phrase "quantum computing" which refers to the word quantum.
Here's a proven (in the lab and mathematically) quantum effect and one of its real world uses that doesn't involve a quantum computer -- just to give you an idea:
https://en.wikipedia.org/wiki/Quantu...g#Tunnel_diode