Type-based Proxy Re-encryption and its Construction

Qiang Tang

    Research output: Book/ReportReportProfessional

    102 Citations (Scopus)
    1351 Downloads (Pure)


    Recently, the concept of proxy re-encryption has been shown very useful in a number of applications, especially in enforcing access control policies. In existing proxy re-encryption schemes, the delegatee can decrypt all ciphertexts targeted to the delegator after re-encryption by the proxy. Consequently, in order to implement fine-grained access control policies, the delegator needs to either use multiple key pairs or trust the proxy to behave honestly. In this paper, we fine-grain this concept and propose type-based proxy re-encryption, which enables the delegator to selectively delegate his decryption right to the delegatee while only needs one key pair. As a result, type-based proxy re-encryption enables the delegator to implement fine-grained policies with one key pair without any additional trust on the proxy. We provide a security model for our concept and provide formal definitions for semantic security and ciphertext privacy which is a valuable attribute in privacy-sensitive contexts. We propose two type-based proxy re-encryption schemes: one is CPA secure with ciphertext privacy while the other is CCA secure without ciphertext privacy.
    Original languageUndefined
    Place of PublicationEnschede
    PublisherCentre for Telematics and Information Technology (CTIT)
    Number of pages23
    Publication statusPublished - Jul 2008

    Publication series

    NameCTIT Technical Report Series
    PublisherUniversity of Twente, Centre for Telematics and Information Technology (CTIT)
    ISSN (Print)1381-3625


    • METIS-251058
    • SCS-Cybersecurity
    • EWI-13024
    • IR-64857

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