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Experts Hail Quantum Computer Memory Stability Breakthrough
cold fjord writes "The BBC reports, 'A fragile quantum memory state has been held stable at room temperature for a "world record" 39 minutes — overcoming a key barrier to ultrafast computers. 'Qubits' of information encoded in a silicon system persisted for almost 100 times longer than ever before. ... "This opens the possibility of truly long-term storage of quantum information at room temperature," said Prof Thewalt ... unofficially, the previous best for a solid state system was 25 seconds at room temperature, or three minutes under cryogenic conditions. ... What's more, they found they could manipulate the qubits as the temperature of the system rose and fell back towards absolute zero. At cryogenic temperatures, their quantum memory system remained coherent for three hours. "Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer," said co-author Stephanie Simmons of Oxford University's department of materials. ... "We've managed to identify a system that seems to have basically no noise." However she cautions there are still many hurdles to overcome before large-scale quantum computations can be performed. ... "This result represents an important step towards realizing quantum devices," said David Awschalom, professor in Spintronics and Quantum Information, at the University of Chicago. "However, a number of intriguing challenges still remain." — Abstract for the paywalled academic paper."
The second they perfect this, they will be able to try all the keys at once and the right one will be solved instantly. All of our current generation of encryption relies on n-p complete algorithms and will become worthless
There is a lot wrong with this.
First of all, quantum computers cannot as far as we know solve NP-complete problems efficiently. There's no known way for that to happen, and most experts expect they cannot. What they can do, is solve specific classes of problems more efficiently than classical computers. The most obvious example of this is factoring integers, which seems to be very difficult for a classical machine, but which can be done quickly by a quantum computer using Shor's algorithm. http://en.wikipedia.org/wiki/Shor's_algorithm
Second, none of these algorithms are instantaneous or even remotely so, but rather scale wit the size of the input, generally with a polynomial.
Third, while many forms of crypto would be vulnerable, including RSA and elliptic curve cryptography, not all forms of cryptography have known vulnerabilities. This connects with the earlier issue of NP completeness. No form of crypto relies at this point on an NP complete problem. Factoring for example is in NP (which means roughly that one can easily convince someone that one actually has the factorization), but it is likely not NP complete. A problem is NP complete if (roughly speaking) it lives in NP, and if you have access to a black box that solves the problem then you can solve all NP problems. At this point, factoring is strongly suspected not to be NP complete, because that would lead to the collapse of the polynomial hierarchy http://en.wikipedia.org/wiki/Polynomial_hierarchy, which is strongly conjectured to occur.
Quantum computers will likely have real world consequences if we ever get them to work on a large scale, and some of those consequences will be cryptographic. But thinking that they'll somehow blow up all cryptography is just hype. If you want to read a good book, without hype, that does a good job of explaining how quantum computing actually works, I recommend "Quantum Computing Since Democritus" by Scott Aaaronson. The book does assume some slight comfort with linear algebra, a very tiny amount of group theory, and some calculus, but that's it. It is aimed at people in technical fields other than quantum computing to understand what it is about. It is highly readable, and I strongly recommend it.
39 minutes.....that's long enough to run Windows between BSODs