Paper 2023/906

Optimal Broadcast Encryption and CP-ABE from Evasive Lattice Assumptions

Hoeteck Wee, NTT Research, École Normale Supérieure - PSL
Abstract

We present a new, simple candidate broadcast encryption scheme for $N$ users with parameter size poly$(\log N)$. We prove security of our scheme under a non-standard variant of the LWE assumption where the distinguisher additionally receives short Gaussian pre-images, while avoiding zeroizing attacks. This yields the first candidate optimal broadcast encryption that is plausibly post-quantum secure, and enjoys a security reduction to a simple assumption. As a secondary contribution, we present a candidate ciphertext-policy attribute-based encryption (CP-ABE) scheme for circuits of a-priori bounded polynomial depth where the parameter size is independent of the circuit size, and prove security under an additional non-standard assumption.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
A minor revision of an IACR publication in EUROCRYPT 2022
Contact author(s)
wee @ di ens fr
History
2023-06-12: approved
2023-06-11: received
See all versions
Short URL
https://ia.cr/2023/906
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/906,
      author = {Hoeteck Wee},
      title = {Optimal Broadcast Encryption and CP-ABE from Evasive Lattice Assumptions},
      howpublished = {Cryptology ePrint Archive, Paper 2023/906},
      year = {2023},
      note = {\url{https://eprint.iacr.org/2023/906}},
      url = {https://eprint.iacr.org/2023/906}
}
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