Broadcast Encryption with Size N^1/3 and More from k-Lin

Hoeteck Wee

Paper 2025/1742

Broadcast Encryption with Size N^1/3 and More from k-Lin

Hoeteck Wee, NTT Research

Abstract

We present the first pairing-based ciphertext-policy attribute-based encryption (CP-ABE) scheme for the class of degree $3$ polynomials with compact parameters: the public key, ciphertext and secret keys comprise $O(n)$ group elements, where $n$ is input length for the function. As an immediate corollary, we obtain a pairing-based broadcast encryption scheme for $N$ users with $O(N^{1/3})$-sized parameters, breaking the long-standing $\sqrt{N}$ barrier for pairing-based broadcast encryption. All of our constructions achieve adaptive security against unbounded collusions, and rely on the (bilateral) $k$-Lin assumption in prime-order bilinear groups.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: A minor revision of an IACR publication in CRYPTO 2021
Contact author(s): wee @ di ens fr
History: 2025-09-25: approved; 2025-09-23: received; See all versions
Short URL: https://ia.cr/2025/1742
License: CC BY

BibTeX

@misc{cryptoeprint:2025/1742,
      author = {Hoeteck Wee},
      title = {Broadcast Encryption with Size N^1/3 and More from k-Lin},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1742},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1742}
}