Registration-Based Encryption from Standard Assumptions

Sanjam Garg, Mohammad Hajiabadi, Mohammad Mahmoody, Ahmadreza Rahimi, Sruthi Sekar

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    6 Scopus citations

    Abstract

    The notion of Registration-Based Encryption (RBE) was recently introduced by Garg, Hajiabadi, Mahmoody, and Rahimi [TCC’18] with the goal of removing the private-key generator (PKG) from IBE. Specifically, RBE allows encrypting to identities using a (compact) master public key, like how IBE is used, with the benefit that the PKG is substituted with a weaker entity called “key curator” who has no knowledge of any secret keys. Here individuals generate their secret keys on their own and then publicly register their identities and their corresponding public keys to the key curator. Finally, individuals obtain “rare” decryption-key updates from the key curator as the population grows. In their work, they gave a construction of RBE schemes based on the combination of indistinguishability obfuscation and somewhere statistically binding hash functions. However, they left open the problem of constructing RBE schemes based on standard assumptions. In this work, we resolve the above problem and construct RBE schemes based on standard assumptions (e.g., CDH or LWE). Furthermore, we show a new application of RBE in a novel context. In particular, we show that anonymous variants of RBE (which we also construct under standard assumptions) can be used for realizing abstracts forms of anonymous messaging tasks in simple scenarios in which the parties communicate by writing messages on a shared board in a synchronized way.

    Original languageEnglish (US)
    Title of host publicationPublic-Key Cryptography – PKC 2019 - 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings
    EditorsDongdai Lin, Kazue Sako
    PublisherSpringer Verlag
    Pages63-93
    Number of pages31
    ISBN (Print)9783030172589
    DOIs
    StatePublished - 2019
    Event22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2019 - Beijing, China
    Duration: Apr 14 2019Apr 17 2019

    Publication series

    NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
    Volume11443 LNCS
    ISSN (Print)0302-9743
    ISSN (Electronic)1611-3349

    Conference

    Conference22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2019
    CountryChina
    CityBeijing
    Period4/14/194/17/19

    All Science Journal Classification (ASJC) codes

    • Theoretical Computer Science
    • Computer Science(all)

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