Quantum Computers Are the Future Nukes of the IT World
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Quantum Computers Are the Future Nukes of the IT World
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Re: Quantum Computers Are the Future Nukes of the IT World
#2Are ordinary ssh keys vulnerable?
Re: Quantum Computers Are the Future Nukes of the IT World
#3Are ordinary ssh keys vulnerable?
Can you elaborate more? In what sense? They are certainly vulnerable if you compromise the system which has them saved. Are they vulnerable to a brute force breach? Likely not, brute force is always a slow process, no matter how you speed it up. Is X vulnerable should always be phrased as Is X vulnerable to Y.
Re: Quantum Computers Are the Future Nukes of the IT World
#4Quantum fintech is going to make blockchain fintech look like child’s play.
Re: Quantum Computers Are the Future Nukes of the IT World
#5Are ordinary ssh keys vulnerable?
Can you elaborate more? In what sense? They are certainly vulnerable if you compromise the system which has them saved. Are they vulnerable to a brute force breach? Likely not, brute force is always a slow process, no matter how you speed it up. Is X vulnerable should always be phrased as Is X vulnerable to Y.
right, brute force your way in without a key
Re: Quantum Computers Are the Future Nukes of the IT World
#6Earlier quoted context omitted.
Can you elaborate more? In what sense? They are certainly vulnerable if you compromise the system which has them saved. Are they vulnerable to a brute force breach? Likely not, brute force is always a slow process, no matter how you speed it up. Is X vulnerable should always be phrased as Is X vulnerable to Y.
right, brute force your way in without a key
I would also add is there additional vulnerability just from an attacker examining the public key with crypto whatchahosy magic
Re: Quantum Computers Are the Future Nukes of the IT World
#7Question: I get that QC can break some cryptosystems, but can it break all known cryptosystems?
Re: Quantum Computers Are the Future Nukes of the IT World
#8Are ordinary ssh keys vulnerable?
If your ssh key relies on RSA, then yes, you're relying on the difficulty of factoring numbers; which Shor's algorithm can perform efficiently. But only if the quantum computer has enough qubits. The needed number of qubits needed to factor is a multiple of the rsa key length. Unlike a regular computer, where you can finagle two computers with 2 gigs of memory to work like a single machine wiht 4 gigabytes of memory, so you can't just merge two 1024 qubit computers to get a 2048 qubit computer. And we're a long way off to having anything close to that.
The simplest solution is simply to increase the size of the key beyond that of the most advanced quantum computer (which is essentially today's approach ;) ). Also, you just need to exchange a symmetric key; Shor's algorithm is a special case, you don't get the exponential -> polynomial speedup[1] to encryption algorithms in general. So once you deliver the symmetric key in a secure way, using a quantum resistant algorithm, you can resume business as usual.
[1] Though in brute force searches, you can reduce the effective key length by 2. https://en.wikipedia.org/wiki/Grover%27s_algorithm
Re: Quantum Computers Are the Future Nukes of the IT World
#9Question: I get that QC can break some cryptosystems, but can it break all known cryptosystems?
Symmetric encryption generally is ok/only weakened, and there's lots of research into solutions: https://en.wikipedia.org/wiki/Post-quantum_cryptography
Re: Quantum Computers Are the Future Nukes of the IT World
#10Question: I get that QC can break some cryptosystems, but can it break all known cryptosystems?
To our knowledge, it cannot. It would be extremely surprising if it could.
However, it can reduce the difficulty of a generic brute force search
https://en.wikipedia.org/wiki/Grover%27s_algorithm
But it only reduces the effective key length by 2. Which, although amazing, has a fairly straightforward response. Double your key length beyond what was previously viewed as 'intractable'.