DKG protocol in hierarchical threshold access structure

A distributed key generation (DKG) protocol is a central segment in distributed cryptosystems. It permits a gathering of members to mutually produce a pair of keys (private key and public key) without assuming any trusted member. The public key is output in clear but only authorised subgroups of members are able to reconstruct or utilize the private key. Existing study on DKG protocols assumes equal authority for members or participants. In this study, the authors consider the issue of DKG in groups with various levelled structure where the authorised subsets can be characterized by a hierarchical threshold access structure. They first propose an verifiable hierarchical threshold secret sharing protocol. On the premise of this development, they then propose another DKG protocol with with hierarchical threshold access structure for discretelogarithm-based cryptosystems. It is demonstrated that the proposed protocols fulfill all the security necessities.