Abstract: Systems and methods for quantum secret splitting based on non-orthogonal multi-particle states are disclosed. The method includes preparing at a sender (“Charlie”) two qubits each of which can be in one of two non-orthogonal states and distributing the qubits to respective parties Alice and Bob. The method also includes measuring at Alice the state of the qubit she receives by a projective measurement so that the measurement result is either 0 or 1, and at Bob measuring the state of the qubit he receives such that the measurement result is either 0, 1 or f, wherein f represents a failure by Bob to properly measure the qubit state. The method also includes communicating between Alice, Bob and Charlie the outcome of their respective measurements so as to deduce the state of the qubits sent to Alice and Bob.

Abstract: Systems and method of enhancing the security of a QKD system having operably coupled QKD stations (Alice, Bob) using correlated photon pulses (P1, P2) are disclosed. The method includes generating the correlated photon pulses at Alice and detecting one of the pulses (P2) to determine the number of photons in the other pulse (P1). Pulse P1 is then randomly modulated to form a modulated pulse P1?, which is transmitted to Bob. Bob then randomly modulates pulses P1? to form twice-modulated pulses P1?. Bob then detects pulses P1? at select timing slots that correspond to the expected arrival times of pulses P1?, as well as to the number of photons in pulse P1 (and thus in P1?). Bob then communicates with Alice to determine the number N1 of single-photon pulses P1? detected and the number N2 of multi-photon pulses P1? detected. A security parameter (SP) is defined based on the probabilities of detecting single-photon and multi-photon pulses.

Abstract: Systems and methods for quantum secret splitting based on non-orthogonal multi-particle states are disclosed. The method includes preparing at a sender (“Charlie”) two qubits each of which can be in one of two non-orthogonal states and distributing the qubits to respective parties Alice and Bob. The method also includes measuring at Alice the state of the qubit she receives by a projective measurement so that the measurement result is either 0 or 1, and at Bob measuring the state of the qubit he receives such that the measurement result is either 0, 1 or ƒ, wherein ƒ represents a failure by Bob to properly measure the qubit state. The method also includes communicating between Alice, Bob and Charlie the outcome of their respective measurements so as to deduce the state of the qubits sent to Alice and Bob.