Patent ID: 7769173

Claim:
A method for executing a bit-commitment protocol for transmitting a bit from a first party to a second party, the method comprising: preparing three qubits in one of two entangled W-states, wherein a first W-state represents one bit value and a second W-state represents a second bit value, two of the three qubits are in a first qubit-basis state, and one of the three qubits is in a second qubit-basis state, wherein the first and second qubit-basis states are two orthogonal polarization states of electromagnetic waves or two atomic nuclear spin states; storing a first qubit of the three qubits in a first storage device controlled by the first party, a second qubit of the three qubits in a second storage device controlled by the second party, and the third qubit of the three qubits in a third storage device controlled by a third party; transmitting the first qubit and the third qubit to the second party; and revealing the bit to the second party by measuring the state qubits to determine which of the two W-states the three qubits are in.