[Wee22] Optimal Broadcast Encryption and CP-ABE from Evasive Lattice Assumptions

Authors: Hoeteck Wee | Venue: EUROCRYPT 2022 | Source

Abstract

We present new constructions of broadcast encryption and ciphertext-policy attribute-based encryption (CP-ABE) for ${\mathsf{NC}}^1$ circuits with optimal parameters — $O(1)$ ciphertext overhead and $O(1)$ public key size — from a new lattice assumption called evasive LWE. Evasive LWE posits that a standard LWE instance remains indistinguishable from uniform even when the adversary is given a trapdoor for a matrix derived from the LWE matrix. The assumption is motivated by the structure of the constructions and is incomparable to standard LWE; it evades known lattice attacks because the trapdoor does not directly help invert the LWE problem.

BibTeX

Copy

@Inproceedings{EC:Wee22,
  author = {Hoeteck Wee},
  title = {Optimal Broadcast Encryption and {CP}-{ABE} from Evasive Lattice Assumptions},
  pages = {217--241},
  editor = {Orr Dunkelman and Stefan Dziembowski},
  booktitle = {Advances in Cryptology -- {EUROCRYPT}~2022, Part~II},
  volume = {13276},
  series = {Lecture Notes in Computer Science},
  address = {Trondheim, Norway},
  month = {may~30~--~jun~3},
  publisher = {Springer, Cham, Switzerland},
  year = {2022},
  doi = {10.1007/978-3-031-07085-3_8},
}