Australian Gov't May Employ a Homegrown Quantum Key System

mask.of.sanity writes "The Australian government is trialling a new Quantum Key Distribution (QKD) system built by Aussie scientists. QKD is considered the world's toughest security because the slightest attempt to intercept the one time keys, coded into lasers at the quantum level, will disrupt the beam. The technology differs from current cryptography tech primarily because it's cheap. Well, less than the $US100k price tag of rival systems. It uses off-the-shelf networking gear instead of proprietary technology, and is built on open standards, so it's easier to install. The random key is encoded at the quantum level in the sidebeam in the phase and amplitude, or brightness and colour, of a highly tuned laser beam. The creators, who built the system in part for their Ph.Ds, said it can be used to transport the most sensitive data like critical infrastructure and secret commercial IP. The days of hand-delivered security keys are numbered."

Re:Wait a minute...

[TinBromide]

So, someone with enough knowledge as to which orientation the key will be encoded on can intercept it and generate a new photon with the same recorded information? Because, as you say, you can't record EVERYTHING about a photon at once, and you destroy it as you filter/record it, wouldn't the receiver destroy it as they filter/record it?

I know that you use a simplified example based on the polarity of the measurements, but if a nefarious evil party had the same equipment configured the same way as the true reciever, he/she could intercept the key and generate a new photon with a passable key?

If the distribution of the keys are based on known, shared configurations, aren't those configurations just a key used to decode/attack the secondary encryption layer of the key? (photon orientation).

one time pad

[Fëanáro]

I do not get the advantages of this system over the one-time pad.
Is there anything this quantum key system could do that a courier carrying a terrabyte drive with a one-time pad once in a while could not?

The quantum key may not be interceptable in theory, but you still have to trust the sending and receiving equipment not to leak anything.
Auditing equipment advanced enough for quantum encryption sounds quite a bit harder than auditing a sealed box with a harddrive and a chip doing XORs for a one-time-pad.
And people with the neccessary trust and clearance AND the skills in quantum physics should be harder to come by.

Plus the bandwith of the quantum channel is low, so they are only sending the keys, and send the encrypted data by normal channels. So you also have to trust the encryption algorithm, while an OTP is provably unbreakable.

Re:Great for them!

[Cimexus]

Guess where a great deal of the US's intelligence data is collected from. Hint: it's a large, dry country within long-range radio distance from China.

Guess where that data gets transmitted back to the US from? Hint: several top-secret joint US-Australian bases located in various places in Central Australia (i.e. the middle of nowhere)

And guess which country has more access to intelligence sharing with the US than any other allied nation (except for the UK)?

Australia's geographic position means a LOT of US intelligence data either is sourced from here or flows through here. So it's in all allied countries interests to have good encryption here ;)

Re:Quantum Leap

[MadMidnightBomber]

Quantum leap: (adj.) literally, to move by the smallest amount theoretically possible. In advertising, to move by the largest leap imaginable (in the mind of the advertiser). There is no contradiction.

- Tonkin's First Computer Dictionary