Almost Optimal KP and CP-ABE for Circuits from Succinct LWE

Hoeteck Wee

Paper 2025/509

Almost Optimal KP and CP-ABE for Circuits from Succinct LWE

Hoeteck Wee, NTT Research

Abstract

We present almost-optimal lattice-based attribute-based encryption (ABE) and laconic function evaluation (LFE). For depth d circuits over $ℓ$ -bit inputs, we obtain * key-policy (KP) and ciphertext-policy (CP) ABE schemes with ciphertext, secret key and public key size $O (1)$ ; * LFE with ciphertext size as well as CRS and digest size ; where O(·) hides poly(d, λ) factors. The parameter sizes are optimal, up to the poly(d) dependencies. The security of our schemes rely on succinct LWE (Wee, CRYPTO 2024). Our results constitute a substantial improvement over the state of the art; none of our results were known even under the stronger evasive LWE assumption.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: A minor revision of an IACR publication in EUROCRYPT 2025
Contact author(s): wee @ di ens fr
History: 2025-03-20: approved; 2025-03-18: received; See all versions
Short URL: https://ia.cr/2025/509
License: CC BY

BibTeX

@misc{cryptoeprint:2025/509,
      author = {Hoeteck Wee},
      title = {Almost Optimal {KP} and {CP}-{ABE} for Circuits from Succinct {LWE}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/509},
      year = {2025},
      url = {https://eprint.iacr.org/2025/509}
}