Delegatable ABE with Full Security from Witness Encryption

Rishab Goyal; Saikumar Yadugiri

Paper 2025/407

Delegatable ABE with Full Security from Witness Encryption

Rishab Goyal, University of Wisconsin-Madison

Saikumar Yadugiri

, University of Wisconsin-Madison

Abstract

Delegatable Attribute-Based Encryption (DABE) is a well-known generalization of ABE, proposed to mirror organizational hierarchies. In this work, we design a fully-secure DABE scheme from witness encryption and other simple assumptions. Our construction does not rely on Random Oracles, and we provide a black-box reduction to polynomial hardness of underlying assumptions. To the best of our knowledge, this is the first DABE construction (beyond hierarchical identity-based encryption) that achieves full security without relying on complexity leveraging. Our DABE supports an unbounded number of key delegations, and the secret key size grows just linearly with each key delegation operation.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Attribute-Based Encryption Witness Encryption Key Delegation
Contact author(s): rishab @ cs wisc edu
saikumar @ cs wisc edu
History: 2025-03-04: approved; 2025-03-03: received; See all versions
Short URL: https://ia.cr/2025/407
License: CC BY

BibTeX

@misc{cryptoeprint:2025/407,
      author = {Rishab Goyal and Saikumar Yadugiri},
      title = {Delegatable {ABE} with Full Security from Witness Encryption},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/407},
      year = {2025},
      url = {https://eprint.iacr.org/2025/407}
}