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Quantum computing calls for new encryption techniques?

  1. Dec 7, 2012 #1
    With the phenomenal speed to be expected from quantum computers in the future, todays encryption techniques such as RSA will be pretty much useless. A quantum computer could factorise 600bit+ numbers in a relatively short period of time. Aside from Shor's algorithm, are there any other mathematicians out there who are trying to invent a new algorithm?

    It just hit me that when quantum computing starts to take over a "new internet" will need to be created. Any security we have at the moment will just be too weak. Networking, programming, websites, wireless, every aspect of security we have today will be completely useless due to the tremendous power that comes with quantum computing.
  2. jcsd
  3. Dec 8, 2012 #2
    My own opinion is that like any computer you really need the hardware first before people can figure out the best ways to program the thing. We don't even know a lot of the science behind quantum computers and it looks like the learning curve will be steep. For example, just recently entanglement has been demonstrated to be contextual. That means the strength of the entanglement is dependent on the number of particles entangled and such basic knowledge could be critical to designing quantum security.
  4. Dec 8, 2012 #3


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    Last edited: Dec 8, 2012
  5. Dec 8, 2012 #4
    This is not the case. Only public key systems are currently at risk, where the cost of cracking the key is the same as the cost of legitimately encrypting something with it. Symmetric cipher strength is only halved by Grover's attack and unaffected by Shor's.

    WPA2 is AES based and will remain secure provided the keylength is long enough. The TLS (secure http) key exchange is at risk, but the actual data encryption (which also uses AES) is not, and rolling out a new key exchange is just an RFC and a few patches away.

    Probably the most widespread use of public key cryptography is in the SSH protocol, but there are barriers to attack there. The most important is that the public key in an SSH channel isn't actually "public" the way it is for say PGP keys. This means risk of attack by Shor's is pretty low, since it operates on the public key (factors it) -- not the encrypted datastream.
  6. Mar 26, 2013 #5
    Currently Quantum computers can only do simple maths such as 3x5=15
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