Adaptively Secure Distributed Broadcast Encryption with Linear-Size Public Parameters
Abstract
Distributed broadcast encryption (DBE) is a variant of broadcast encryption (BE) that can efficiently transmit a message to a subset of users, in which users independently generate user private keys and user public keys instead of a central trusted authority generating user keys. In this paper, we propose a DBE scheme with constant size ciphertexts, constant size private keys, and linear size public parameters, and prove the adaptive security of our DBE scheme under static assumptions in composite-order bilinear groups. The previous efficient DBE schemes with constant size ciphertexts and constant size private keys are proven secure under the -Type assumption or have a drawback of having quadratic size public parameters. In contrast, our DBE scheme is the first DBE scheme with linear size public parameters proven adaptively secure under static assumptions in composite-order bilinear groups.
Cite
@article{arxiv.2505.17527,
title = {Adaptively Secure Distributed Broadcast Encryption with Linear-Size Public Parameters},
author = {Kwangsu Lee},
journal= {arXiv preprint arXiv:2505.17527},
year = {2025}
}