At 08:56 PM 8/30/02 -0700, AARG!Anonymous wrote: >Bear writes: >> In this case you'd need to set up the wires-and-gates model >> in the QC for two ciphertext blocks, each attached to an >> identical plaintext-recognizer function and attached to the >> same key register. Then you set up the entangled state, >> and collapse the eigenvector on the eigenstate where the >> ciphertext for block A and block B is produced, and the >> plaintext recognizer for both block A and block B return >> "1", and then you'd read the plaintext and key out of the >> appropriate locations (dots?) in the qchip. > >The problem is that you can't forcibly collapse the state vector into your >wished-for eigenstate, the one where the plaintext recognizer returns a 1. >Instead, it will collapse into a random state, associated with a random >key, and it is overwhelmingly likely that this key is one for which the >recognizer returns 0.
I thought the whole point of quantum-computer design is to build systems where you *do* impose your arbitrary constraints on the system. The whole difficult part of q-computer design is getting enough qubits to sit still to q-search the space of solutions (to Bear's Feistel-gates-machine), subject to your specific constraints (eg., here's a chunk of ciphertext; here's a function which discriminates noise from likely plaintext, or a set of likely plaintexts). The *whole problem* is calculating/enforcing your problem constraints on the q-system. No different from a sim annealing or evolution run, where all the domain-tricks are in the eval function. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]