Paper 2026/2094
Tree Encodings IV: Depth-Unbounded Attribute-Based Encryption and Delay Encryption
Abstract
Assuming the polynomial-time hardness of Decomposed LWE, a variant of the learning with errors (LWE) problem, we construct ciphertext-policy attribute-based encryption for depth-unbounded (but bounded-space) predicates. Previously, attribute-based encryption for depth-unbounded predicates was only known from an insecure version of evasive LWE, or by additionally assuming the cryptographic hardness of discrete logarithms, which makes such schemes quantum-insecure. Adapting these techniques, we also obtain the first construction of lattice-based delay encryption [Burdges and De Feo, EUROCRYPT'21], additionally assuming the existence of any space-bounded sequential function. Finally, as a contribution of independent interest, we show how to instantiate the latter from a circular variant of decomposed LWE. This also gives the first delay encryption that does not require explicit sequentiality assumptions.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Preprint.
- Keywords
- Attribute-based EncryptionLattice-based CryptographyDelay Encryption
- Contact author(s)
-
abram damiano @ protonmail com
giulio malavolta @ unibocconi it
ldr709 @ gmail com - History
- 2026-09-22: approved
- 2026-09-18: received
- See all versions
- Short URL
- https://ia.cr/2026/2094
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2026/2094,
author = {Damiano Abram and Giulio Malavolta and Lawrence Roy},
title = {Tree Encodings {IV}: Depth-Unbounded Attribute-Based Encryption and Delay Encryption},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/2094},
year = {2026},
url = {https://eprint.iacr.org/2026/2094}
}
