Paper 2026/465

Advanced cryptography from lattice isomorphism—new constructions of IBE and FHE

Huck Bennett, University of Colorado Boulder
Zhengnan Lai, Cornell University
Noah Stephens-Davidowitz, Cornell University
Abstract

We show how to translate some of the more advanced techniques used in LWE-based cryptography to the setting of lattice-isomorphism-based cryptography, which was recently introduced by Ducas and van Woerden [Eurocrypt, 2022]. In particular, we show constructions of two powerful cryptographic primitives, identity-based encryption (IBE) and leveled fully homomorphic encryption (FHE). We then prove their security under the assumption that a suitable version of the Lattice Isomorphism Problem is hard. Our constructions use quite general and modular techniques, and we expect them to have other applications. Specifically, we show that the now-ubiquitous techniques introduced by Gentry, Peikert, and Vaikuntanathan [STOC, 2008] to build IBE and Gentry, Sahai, and Waters [Crypto, 2013] to build FHE can be made to work in our setting using any sufficiently ``nice'' lattice.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
A minor revision of an IACR publication in CRYPTO 2026
Keywords
lattice isomorphismfully homomorphic encryptionidentity-based encryptionlattice-based cryptography
Contact author(s)
huck bennett @ colorado edu
zl345 @ cornell edu
noahsd @ gmail com
History
2026-07-28: revised
2026-03-05: received
See all versions
Short URL
https://ia.cr/2026/465
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/465,
      author = {Huck Bennett and Zhengnan Lai and Noah Stephens-Davidowitz},
      title = {Advanced cryptography from lattice isomorphism—new constructions of {IBE} and {FHE}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/465},
      year = {2026},
      url = {https://eprint.iacr.org/2026/465}
}
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