My question is: how practical would it be to use a 1TB RSA key for average users? I assume that the size of cipher text would be somewhat depended on secret size.
The storage space and network bandwidth is not free.
Why Quantum Computers Might Not Break Cryptography
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Re: Why Quantum Computers Might Not Break Cryptography
#22Who gives a damn about a terabyte size key? what a pointless article.
Re: Why Quantum Computers Might Not Break Cryptography
#23I feel like the paper by DJB, which this article is based off of, was some sort of satire.
It absolutely is - one of the keywords is "Make RSA Great Again", ffs.
Re: Why Quantum Computers Might Not Break Cryptography
#24If I had a quantum computer that was capable of breaking RSA, I wouldn't tell anyone. The whole point is to be able to spy on people, and you wouldn't be able to do that if everyone knew that RSA was broken. I don't know if quantum computers exist, but I'm sure once they do, the people who build them will keep them secret.
A high-end desktop is better at simulating quantum computers than any that we've ever built [1]. The best quantum computers achieve about 10 qubits. Furthermore, quantum operations are slower than classical operations. A classical computer can do a 64-bit operation (depending on clock speed) in ~0.25ns, a quantum computer takes about 5ns. Also, quantum computers don't scale like classical computers. 2 classical computers can solve twice as many problems or problems twice as hard, while 2 quantum computers can only solve twice as many problems.
The hard part is hardware, and you need the minimum number of qubits to be of any use to breaking RSA. That number is on the order of O(N^2), where N is the number of bits--so you need qubits on the order of hundreds of thousands if not millions. Where the state of the art is around 10.
[1] D-Wave is approaching this equivalency, for certain definitions of quantum computers.
Re: Why Quantum Computers Might Not Break Cryptography
#25I am worried about the following part from the paper " rel="nofollow">https://cr.yp.to/papers/pqrsa-20170419.pdf> "Our batch prime-generation algorithm suggests that, to help reduce energy consumption and protect the environment, all users of RSA — including users of traditional pre-quantum RSA — should delegate their key-generation computations to NIST or anohter trusted third party. This speed improvement would als…
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Re: Why Quantum Computers Might Not Break Cryptography
#26I am worried about the following part from the paper " rel="nofollow">https://cr.yp.to/papers/pqrsa-20170419.pdf> "Our batch prime-generation algorithm suggests that, to help reduce energy consumption and protect the environment, all users of RSA — including users of traditional pre-quantum RSA — should delegate their key-generation computations to NIST or anohter trusted third party. This speed improvement would als…
I find their assertion somewhat disingenuous, in security things are often done (and known to be and deliberately done) in rather inefficient manners - for example algorithms that run in fixed time despite obvious case specific optimisations.
We'd probably be far better off coming up with mechanisms to generate strongly probabilistically unique psudeo-random domains from which we could (on a per cryptographic context basis) generate strong pseudo-primes.
This could most likely be done in a reasonably efficient manner, without resorting to the government backdoor suggested.