Masking Quantum Information is Impossible

Abstract

Classical information encoded in composite quantum states can be completely hidden from the reduced subsystems and may be found only in the correlations. Can the same be true for quantum information? If quantum information is hidden from subsystems and spread over quantum correlation, we call it masking of quantum information. We show that while this may still be true for some restricted sets of nonorthogonal quantum states, it is not possible for arbitrary quantum states. This result suggests that quantum qubit commitment-a stronger version of the quantum bit commitment-is not possible in general. Our findings may have potential applications in secret sharing and future quantum communication protocols.

Quantum information capsule in multiple-qudit systems and continuous-variable systems

“…This example shows that maximally entangled partners do not exist in general. The fact that information can be hidden from the subsystems perfectly only in specific situations is consistent with the results in [14,15], though our setup is different from theirs.…”

No-go results in quantum thermodynamics

“…Let us suppose that there exists a joint unitary V acting on both the system and ancillary qubit as, Proof. Quantum no masking theorem [4], which has a connection to the impossibilities of (2, 2) secret sharing in [31], states that it is impossible to construct a unitary U such that U |ψ…”

“…The first law is simply the energy conservation principle, whereas the second law specifies the direction of any spontaneous process [1]. On the other hand, the rich algebraic structure of quantum mechanics prohibits the execution of several information processing tasks [2][3][4][5][6][7][8][9][10]. The implication of these no-go theorems as a consequence of thermodynamic principles is a field of recent interest [11][12][13][14].…”

Masking quantum information in multipartite scenario

“…Firstly, instead of hiding quantum information in bipartite quantum system, we hide them in multipartite ones. So we need to generalize the definition of masking of quantum states which is almost the same as that in [11]. Definition 1.…”