Masking quantum information is impossible

TL;DR

This paper investigates the possibility of hiding quantum information in correlations, concluding that quantum information cannot be masked for arbitrary states, impacting quantum communication and cryptography.

Contribution

It proves that quantum information masking is impossible for arbitrary states, extending the understanding of quantum information security.

Findings

Masking quantum information is only possible for restricted sets of states.

Quantum masking cannot be achieved for all quantum states.

Implications for quantum cryptography and secret sharing protocols.

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 as masking of quantum information. We show that while this may still be true for some restricted sets of non-orthogonal 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.