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Quantum Cryptography Is Safe Again
sciencehabit writes "In theory, so-called quantum cryptography provides a totally secure way of sending information. In practice, maybe not. But now physicists have demonstrated how to close a technological loophole that could have left secrets open to eavesdroppers. '[I]n 2010, an international team of researchers showed that [an attacker] could hack the system by exploiting a weakness in the so-called avalanche photodiodes (APDs) used to detect the individual photons. The problem is that APDs react differently to intense pulses of light than they do to single photons, so that the energy of the pulse must exceed a threshold to register a hit. As a result, all [the attacker] has to do is intercept the single photons, make her best-guess measurements of their polarizations, and send her answers off to Bob as new, brighter pulses. ... Last year, physicist Hoi-Kwong Lo at the University of Toronto and colleagues claimed to find a way around the problem. In the new protocol, Alice and Bob would begin the creation of a quantum key by sending randomly polarized signals to Charlie, a third party. Charlie would measure the signals to determine not their actual polarization, but only whether the polarizations were at right angles. ... Now, in papers in press at Physical Review Letters, two independent groups of physicists have shown that the new protocol works.'"
In the so-called summary, there is a lot of so-called repetition of a silly phrase. It's not just a so-called avalanche photodiode, that's what it is.
Quantum Cryptogaphy exists in a superposition of simultaneously being secure and not-secure.
(Eh, somebody was gonna...)
=Smidge=
So in order to achieve the ultimate in secure two-party communications, we need a third party?
Ok, Ok, I'll go read the rest of the article.
Yes, you can reason that quantum cryptography is going to protect this and that thing that isn't at the consumer level. Good on it. But you're still going to have people typing "password" as their password at their bank or "Jeremy85", the boy in the photo on their desk and his year of birth, in sensitive work email.
Laughter is the Spackle of the Soul.
Is quantum entanglement the only physical resource that allows for such strong encryption?
I.e. does exploiting thermodynamic properties already suffice as claimed in the Kish cypher?
Why are people interested in quantum cryptography at all when they can't even get it togeather enough to use SSL. Instead they blame the NSA for viewing all the endless plain text they insist on sending.
So what we have is the following :)
- Quantum security is secure if no one is actually probing it -- just like all other security
- A quantum security device of low quality (cheap electronics/APDs) is more vulnerable than better equipment
That quantum encryption system that we weren't using, weren't evaluating, and weren't even capable of implementing, has been saved!
The Space Family Robinson can now safely move on to their next adventure.
Is quantum entanglement the only physical resource that allows for such strong encryption?
The original quantum crypto protocol BB84 http://en.wikipedia.org/wiki/BB84 does not require entanglement, and is secure if one is still sending single photons at a time.
Excuse my extreme ignorance why not use single photons? This seems to now be possible.
So anyway we now trust Charlie to generate trustworthy answers over purely classical channels? What keeps Charlie from telling lies at what consequence?
Cryptography safe? Ha ha ha ha!!!
Quantum modulation (and no, it is not "encryption") cannot be routed. The Internet only became possible when global routing rules were introduced. In fact, the Internet can well be described as the "IP routing domain". Its properties mean that quantum modulation will never scale and always only be good for site-to-site links. But these can be protected better, cheaper and more securely in other ways. For example, for site-to-site links, one-time-pads become practical. Quantum modulation is so terribly slow, that it will only be used to transfer keys, that are then used for conventional encryption, the dirty secret behind this technology. But for that, one-time-pads (in this scenario list of one-time keys) are far, far superior.
When will this BS finally end? This technology has zero rational use.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.