Quantum Cryptography Leaving the Lab

Theodore Logan writes "More than a year ago, MagiQ announced the world's first commercial quantum cryptography system (pdf), with ID Quantique following closely in their footsteps. Currently, the technology is limited to offering point-to-point connections up to a maximum distance of around 50 km, but this is likely to be greatly improved on in coming years. The systems available today are prohibitely expensive for the average Joe (MagiQ's are priced at more than $50,000 per unit), but one could envision a future in which they are built into the infrastructure by non-end user actors. Does this spell the end of the field of cryptography? Will systems like this ever become commonplace, or will they be reserved for sensitive financial transactions and military applications? What impact will quantum cryptography have on society? Good articles available from International Herald Tribune, EE Times and CNET."

Comments

Quantum Cryptography

[Anonymous Coward]

I never understood how quantum cryptography is not vulnerable to normal man in the middle attacks. Anyone care to explain?

Re:It's worse than that, it's physics Jim

[TedCheshireAcad]

It's nice for creating secure point-to-point links, but that's only roughly half of data security. Transmission security is great, but what happens when someone steals the hard drive out of the server?

With all due respect to the quantum guys, the traditional byte-crunching cryptography kind of has the market by the balls here.

Re:It's worse than that, it's physics Jim

[jbf]

Being a networking geek as well as a security geek, I'll point out that the way Internet routing currently works, based on the commercial nature of the Internet, means that almost no routes are symmetric. This is because policies like hot potato routing, where one provider tries to get rid of a packet as quickly as possible. For example, if Sprint and UUNET have exchanges in San Francisco and DC, and a packet goes from a Sprint customer in Sacramento to a UUNET customer in Baltimore, the packet from Sac to Baltimore will go Sprint to San Fran and UUNET the rest of the way, but the return packet will go UUNET to DC and Sprint the rest of the way.

Also, hop-by-hop security is not end-to-end security, so even if you do have all the routers in IPv8 using hop-by-hop encryption over petabit links, you'll still need end-to-end security.

So to answer the question in the post, unless you can afford a leased line with a single fiber, and that fiber is lossless enough to not need repeaters, this is only for things like financial institutions and spy networks.

Not a question of if, but when

[dmccarty]

Every cipher scheme, from the Greeks' steganography to the Romans' alphabet substitution to today's 3DES and other schemes, has eventually been broken. It's unreasonable to believe that quantum cryptography will be invulnerable to attacks forever. It's not a question of if it can be broken, but rather when it will be broken.

Perhaps someone will discover a work-around to Heisenberg's uncertainty principle, or perhaps researchers will find flaws in the implementation of the algorithm. But if history is any indication of the future, quantum cryptography will eventually be cracked.

Solving the wrong problem

[Paul Johnson]

Quantum crypto is only useful over point to point for short distances because it relies on properties of photons that cannot be amplified (if they could be amplified then you could clone the signal and the security would be lost). Its also very very slow (kilobits per second at best). The way it is used is as a key distribution system. The heavy lifting of actually transmitting the data is done by ordinary crypto. So its no stronger than the ordinary crypto. The only thing in favour of quantum key distribution is that you can change the key very frequently.

But these days if you want to intercept data then cracking the crypto is one of the last avenues you would try anyway. Far easier to crack the end points, suborn a trusted employee or any of the other common attacks. Security is only as strong as the weakest link. Quantum crypto merely reinforces one of the strongest links.