Function-private Conditional Disclosure of Secrets and Multi-evaluation Threshold Distributed Point Functions
Abstract
Conditional disclosure of secrets (CDS) allows multiple parties to reveal a secret to a third party if and only if some pre-decided condition is satisfied. In this work, we bolster the privacy guarantees of CDS by introducing function-private CDS wherein the pre-decided condition is never revealed to the third party. We also derive a function secret sharing scheme from our function-private CDS solution. The second problem that we consider concerns threshold distributed point functions, which allow one to split a point function such that at least a threshold number of shares are required to evaluate it at any given input. We consider a setting wherein a point function is split among a set of parties such that multiple evaluations do not leak non-negligible information about it. Finally, we present a provably optimal procedure to perform threshold function secret sharing of any polynomial in a finite field.
Cite
@article{arxiv.2110.04293,
title = {Function-private Conditional Disclosure of Secrets and Multi-evaluation Threshold Distributed Point Functions},
author = {Nolan Miranda and Foo Yee Yeo and Vipin Singh Sehrawat},
journal= {arXiv preprint arXiv:2110.04293},
year = {2021}
}
Comments
The is the full version of the paper that will appear in Cryptology and Network Security (CANS), 2021