{
  "id": "quant-ph/0403148",
  "version": "v2",
  "published": "2004-03-20T13:25:45.000Z",
  "updated": "2005-01-11T09:46:04.000Z",
  "title": "Robustness of the BB84 quantum key distribution protocol against general coherent attacks",
  "authors": [
    "Georgios M. Nikolopoulos",
    "Gernot Alber"
  ],
  "comment": "New improved version. A minor mistake has been eliminated",
  "journal": "Eur. Phys. J. D 37, 441 (2006)",
  "doi": "10.1140/epjd/e2005-00314-3",
  "categories": [
    "quant-ph"
  ],
  "abstract": "It is demonstrated that for the entanglement-based version of the Bennett-Brassard (BB84) quantum key distribution protocol, Alice and Bob share provable entanglement if and only if the estimated qubit error rate is below 25% or above 75%. In view of the intimate relation between entanglement and security, this result sheds also new light on the unconditional security of the BB84 protocol in its original prepare-and-measure form. In particular, it indicates that for small qubit error rates 25% is the ultimate upper security bound for any prepare-and-measure BB84-type QKD protocol. On the contrary, for qubit error rates between 25% and 75% we demonstrate that the correlations shared between Alice and Bob can always be explained by separable states and thus, no secret key can be distilled in this regime.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2005-01-11T09:46:04.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.67.Dd",
      "03.67.Hk"
    ],
    "keywords": [
      "general coherent attacks",
      "distribution protocol",
      "bb84 quantum",
      "prepare-and-measure bb84-type qkd protocol",
      "robustness"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "European Physical Journal D",
      "year": 2006,
      "month": "Mar",
      "volume": 37,
      "number": 3,
      "pages": 441
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2006EPJD...37..441N"
    }
  }
}