{
  "annotation_id": "3185460b-32d7-4aa1-bda9-762f8930ee66",
  "date_created": "2026-03-02T18:02:13.281000Z",
  "date_modified": "2026-03-02T18:02:13.281000Z",
  "file_hash": "d47492d46b60ea455594d377acdc0844efc87b1fd15eeb884a51cd470b31d6b7",
  "private": false,
  "record": {
    "abstract": "We analyze the set of two-qubit states from which a secret key can be\nextracted by single-copy measurements plus classical processing of the\noutcomes. We introduce a key distillation protocol and give the corresponding\nnecessary and sufficient condition for positive key extraction. Our results\nimply that the critical error rate derived by Chau, Phys. Rev. A {\\bf 66},\n060302 (2002), for a secure key distribution using the six-state scheme is\ntight. Remarkably, an optimal eavesdropping attack against this protocol does\nnot require any coherent quantum operation.",
    "arxiv_id": "quant-ph/0411092",
    "authors": [
      "A. Ac\u00edn",
      "J. Bae",
      "E. Bagan",
      "M. Baig",
      "Ll. Masanes",
      "R. Mu\u00f1oz-Tapia"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.73.012327",
    "journal_ref": "Phys. Rev. A 73, 012327 (2006)",
    "title": "Secrecy content of two-qubit states",
    "url": "https://arxiv.org/abs/quant-ph/0411092"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "07fa5c8b-3d55-4123-b040-4f4420a0487f",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}