Imagine a world with no cyber secrets

I saw this posted over at Windows 7 Forums and thought I would share it here!

Imagine a world with no cyber secrets

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Quantum computers cannot break symmetric ciphers like they can asymmetric ciphers (for public key crypto). It was proved in the 90's that they can only decrease the complexity of a symmetric cipher, like AES, by n/2 bits. So AES-128 will be reduced to 64 bits. However, that's why NIST required 256 bit keys during the AES competition.

So, yes, public keys will all be worthless, but your symmetrically encrypted stuff wont be if you use sufficient key lengths (like 256 bits).

(P.S. A lot of cryptologists do not like quantum crypto -- they think it is a game being played by the physicists who don't understand practical security).

EDIT: Do not confuse quantum crypto with quantum computing. They have nothing to do with each other and I am not sure why the author mentioned quantum crypto. He also wrongly states that quantum computers will break all current crypto. That is incorrect as I explained above.

 

Security and privacy methods will always be changing. It's an ever evolving arms race. Once quantum computing becomes commonplace, quantum computing will be leveraged to create new asymmetric cyphers that are secure.
As for symmetric cyphers, quantum computers will not be much use at brute force key guessing but they could be used to find weakness in current cyphers.
Then of course quantum computers will enable cryptographers to design new cyphers that can't be broken with quantum computers.
As for quantum cryptography, that is more of a novelty that physicists use to write research grant proposals.