Quantum Key Distribution Based on Multi-qubit Hadamard Matrices

A deterministic one-step quantum key distribution scheme is proposed based on multi-qubit Hadamard matrices. In our proposed scheme, the secret key, which is encoded and decoded by using multi-qubit Hadamard transform, is deterministic. In addition, we also discuss in some detail how this protocol must be carefully designed for correcting errors and checking eavesdropping. This protocol is secure under the well-known assumption that the classical channel cannot be modified. It also has an advantage of not exchanging any other classical information except for eavesdropping check.