4 ms·
How many qubit does it take to crack an AES 192 key?
by jest7325 9y ago
How many qubit does it take to crack an AES 192 key?
- rootw0rm 9y agoA lot, considering you'd need 2^96 quantum operations.
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- posixplz 9y agoMost postulations I've seen follow the axiom that the number of qubits must be no less than twice the number of bits used to generate the key. I found a pretty good summary of that thinking on StackExchange: https://security.stackexchange.com/questions/87345/how-many-qubits-are-needed-to-factor-2048-bit-rsa-keys-on-a-quantum-computer https://security.stackexchange.com/questions/87345/how-many-...
- jcranmer 9y agoFor AES, the quantum advantage is merely grover's algorithm, which allows you to invert a function in O(sqrt(N)) time instead of O(N) time. Basically, the algorithm would look like "compute AES-192 on a uniform random quantum state, then do Grover's algorithm for 2^96 timesteps." This needs as many qubits as it takes to compute AES-192 (which, since the algorithm isn't unitary, is strictly greater than 192 qubits). More important is the fact that it's a very long-running application: it requires to you keep over 192 qubits coherent for a very long time, which is probably an order of magnitude or more in error correction requirements.