Paper 2025/290
Dynamic Decentralized Functional Encryption: Generic Constructions with Strong Security
Abstract
Dynamic Decentralized Functional Encryption (DDFE) is a generalization of Functional Encryption which allows multiple users to join the system dynamically without interaction and without relying on a trusted third party. Users can independently encrypt their inputs for a joint evaluation under functions embedded in functional decryption keys; and they keep control on these functions as they all have to contribute to the generation of the functional keys. In this work, we present new generic compilers which, when instantiated with existing schemes from the literature, improve over the state-of-the-art in terms of security, computational assumptions and functionality. Specifically, we obtain the first adaptively secure DDFE schemes for inner products in both the standard and the stronger function-hiding setting which guarantees privacy not only for messages but also for the evaluated functions. Furthermore, we present the first DDFE for inner products whose security can be proven under the LWE assumption in the standard model. Finally, we give the first construction of a DDFE for the attribute-weighted sums functionality with attribute-based access control (with some limitations). All prior constructions guarantee only selective security, rely on group-based assumptions on pairings, and cannot provide access control.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- A major revision of an IACR publication in PKC 2025
- Keywords
- Functional EncryptionAdaptive SecurityFunction-HidingInner ProductAttribute-Weighted Sum
- Contact author(s)
-
ky nguyen @ ens psl eu
david pointcheval @ ens fr
robert schaedlich @ ens fr - History
- 2025-02-20: approved
- 2025-02-19: received
- See all versions
- Short URL
- https://ia.cr/2025/290
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/290, author = {Ky Nguyen and David Pointcheval and Robert Schädlich}, title = {Dynamic Decentralized Functional Encryption: Generic Constructions with Strong Security}, howpublished = {Cryptology {ePrint} Archive, Paper 2025/290}, year = {2025}, url = {https://eprint.iacr.org/2025/290} }