Lattice-Inspired Broadcast Encryption and Succinct Ciphertext-Policy ABE

Zvika Brakerski and Vinod Vaikuntanathan

Abstract

We propose a candidate ciphertext-policy attribute-based encryption (CP-ABE) scheme for circuits, where the ciphertext size depends only on the depth of the policy circuit (and not its size). This, in particular, gives us a Broadcast Encryption (BE) scheme where the size of the keys and ciphertexts have a poly-logarithmic dependence on the number of users. This goal was previously only known to be achievable assuming ideal multilinear maps (Boneh, Waters and Zhandry, Crypto 2014) or indistinguishability obfuscation (Boneh and Zhandry, Crypto 2014) and in a concurrent work from generic bilinear groups and the learning with errors (LWE) assumption (Agrawal and Yamada, Eurocrypt 2020). Our construction relies on techniques from lattice-based (and in particular LWE-based) cryptography. We analyze some attempts at cryptanalysis, but we are unable to provide a security proof.

Available format(s)
Category
Foundations
Publication info
Preprint. MINOR revision.
Keywords
Contact author(s)
vinodv @ mit edu
History
2021-04-26: revised
See all versions
Short URL
https://ia.cr/2020/191

CC BY

BibTeX

@misc{cryptoeprint:2020/191,
author = {Zvika Brakerski and Vinod Vaikuntanathan},
title = {Lattice-Inspired Broadcast Encryption and Succinct Ciphertext-Policy ABE},
howpublished = {Cryptology ePrint Archive, Paper 2020/191},
year = {2020},
note = {\url{https://eprint.iacr.org/2020/191}},
url = {https://eprint.iacr.org/2020/191}
}

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