Information Security and Cryptography Research Group

Secret Key Agreement Over a Non-authenticated Channel — Part III: Privacy Amplification

Ueli Maurer and Stefan Wolf

IEEE Transactions on Information Theory, vol. 49, no. 4, pp. 839–851, Apr 2003.

This is the third part of a three-part paper on secret-key agreement secure against active adversaries. Here, we consider the special case where the legitimate partners already share a mutual string which might, however, be partially known to the adversary. The problem of generating a secret key in this case has been well studied in the passive-adversary model|for instance in the context of quantum key agreement|under the name of privacy amplification. We consider the same problem with respect to an active adversary and propose two protocols, one based on universal hashing and one based on extractors, allowing for privacy amplification secure against an adversary whose knowledge about the initial partially secret string is limited to one third of the length of this string. Our results are based on novel techniques for authentication secure even against adversaries knowing a substantial amount of the “secret” key.

BibTeX Citation

    author       = {Ueli Maurer and Stefan Wolf},
    title        = {Secret Key Agreement Over a Non-authenticated Channel --- {Part~III}: Privacy Amplification},
    journal      = {IEEE Transactions on Information Theory},
    pages        = {839--851},
    number       = {4},
    volume       = {49},
    year         = {2003},
    month        = {4},

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