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Quantum Computing and Optically Controlled Electrons
eldavojohn writes "Researchers have released a new paper on quantum computing theorizing how to use optically controlled electrons to make an ultrafast quantum computer. From the article, "Scientists have designed a scheme to create one of the fastest quantum computers to date using light pulses to rotate electron spins, which serve as quantum bits. This technique improves the overall clock rate of the quantum computer, which could lead to the fastest potentially scalable quantum computing scheme of which the scientists are aware.""
Because a quantum computer does fundamentally more at each clock.
Factoring an 1000-bigt integer takes CPU centuries on modern procesors but would be just afew million operations for a quantum computer.
You wouldn't want a quantum based computer unless you had some type of problem that could be broken down into appropriate search spaces that are compatible with quantum based computing. You won't be seeing massive speedups in Quake 4 with this, you won't see Windows Xp/Vista start up any faster, that's not how they work.
I don't need to test my programs.. I have an error correcting modem.
Well, in short they are going nuts because they simply can't do that. While quantum cryptographic analysis can break existing encryption methods that rely on factoring, new methods are being developed that are safe and secure. No system, however sophisticated, can crack the one time pad provided complete shannon security is maintained.
Quantum Cryptography in that case is using the normal cryptographic method , just use a secure line to exchange the private key. But once the data are stored and the public key is known, it does not matter whether the private key has been transmitted on secure line or NOT. It is only a matter of cracking the crypto-algorithm itself which is then as weak against quantum computer factorisation. The only way to avoid that would be to get ride of public/private key system altogether, and use an OTP as key transmitted on a secure QC line.
But in the very end, QC is only a way of transmission without eavesdropping. It is NOT an encryption algorithm.
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Don't get too excited-- most quantum computing ideas are rather far-fetched-- there are really hard roadblocks that are theoretically and practically very hard to solve. The basic one is you have to keep all the electrons from interacting in ANY WAY with the rest of the universes for a considerable length of time (on the quantum scale). The slightest interaction with anything else and the quantum magic goes *poof*.