International Association for Cryptologic Research

International Association
for Cryptologic Research


Decentralized Multi-authority ABE for $\textsf{NC}^1$ from BDH

Pratish Datta
Ilan Komargodski
Brent Waters
DOI: 10.1007/s00145-023-09445-7
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Abstract: Decentralized multi-authority attribute-based encryption ( $$\textsf{MA}$$ MA - $$\textsf{ABE}$$ ABE ) is a strengthening of standard ciphertext-policy attribute-based encryption so that there is no trusted central authority: Any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters. Essentially, any party can act as an authority for some attribute by creating a public key of its own and issuing private keys to different users that reflect their attributes. This paper presents the first $$\textsf{MA}$$ MA - $$\textsf{ABE}$$ ABE proven secure under the standard search variant of bilinear Diffie–Hellman ( CBDH ) and in the random oracle model. Our scheme supports all access policies captured by $$\textsf{NC}^1$$ NC 1 circuits. All previous constructions were proven secure in the random oracle model and additionally were based on decision assumptions such as the DLIN assumption, non-standard q -type assumptions, or subspace decision assumptions over composite-order bilinear groups.
  title={Decentralized Multi-authority ABE for $$\textsf{NC}^1$$ from BDH},
  journal={Journal of Cryptology},
  author={Pratish Datta and Ilan Komargodski and Brent Waters},