Deciding whether a quantum state has secret correlations is an NP-complete problem
<|reference_start|>Deciding whether a quantum state has secret correlations is an NP-complete problem: From the NP-hardness of the quantum separability problem and the relation between bipartite entanglement and the secret key correlations, it is shown that the problem deciding whether a given quantum state has secret correlations in it or not is in NP-complete.<|reference_end|>
@article{lee2006deciding,
    title={Deciding whether a quantum state has secret correlations is an
  NP-complete problem},
    author={Jae-Weon Lee, DoYong Kwon, Jaewan Kim},
    journal={arXiv preprint arXiv:quant-ph/0612052},
    year={2006},
    archivePrefix={arXiv},
    eprint={quant-ph/0612052},
    primaryClass={quant-ph cs.IT math.IT}
}