International Association for Cryptologic Research

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Limits on Adaptive Security for Attribute-Based Encryption

Authors:
Zvika Brakerski , Weizmann Institute of Science
Stav Medina , Weizmann Institute of Science
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Presentation: Slides
Conference: TCC 2024
Abstract: This work addresses the long quest for proving full (adaptive) security for attribute-based encryption (ABE). We show that in order to prove full security in a black-box manner, the scheme must be "irregular" in the sense that it is impossible to "validate" secret keys to ascertain consistent decryption of ciphertexts. This extends a result of Lewko and Waters (Eurocrypt 2014) that was only applicable to straight-line proofs (without rewinding). Our work, therefore, establishes that it is impossible to circumvent the irregularity property using creative proof techniques, so long as the adversary is used in a black-box manner. As a consequence, our work provides an explanation as to why some lattice-based ABE schemes cannot be proven fully secure, even though no known adaptive attacks exist.
BibTeX
@inproceedings{tcc-2024-34625,
  title={Limits on Adaptive Security for Attribute-Based Encryption},
  publisher={Springer-Verlag},
  author={Zvika Brakerski and Stav Medina},
  year=2024
}