A Quantum Algorithm using NMR Computers to Break Secret-key Cryptosystems

摘要

In this paper, we discuss quantum algorithms that, for a given plaintext m_0 and a given ciphertext c_0, will find a secret key, k_0, satisfying c_0 = E(k_0, m_0). where an encryption algorithm, E, is publicly available. We propose a new algorithm suitable for an NMR (Nuclear Magnetic Resonance) computer based on the technique used to solve the counting problem. The complexity of our algorithm decreases as the measurement accuracy of the NMR computer increases. We discuss the possibility that the proposed algorithm is superior to Grover's algorithm based on initial experimental results.