A Dynamic Proactive Secret Sharing Scheme for Quadratic Functions
H. Chen, Liang Feng Zhang · IEEE Access · 2024
Dynamic proactive secret sharing(DPSS) allows a client to share a secret s among a committee ofnparticipants and allows the committee to reshare the secret among a new committee ofnparticipants such that the secretscan be reconstructed by any authorized subset of the new committee but an adversary that corrupts both members from the old committee and members from the new committee learns no information abouts. The existing DPSS schemes only allow the old committee to reshare thesamesecretsto the new committee. In this paper, we considerdynamic proactive functional secret sharing (DPFSS), a new model for DPSS that allows the old committee to reshare functions of the original secret s among the new committee, and construct a DPFSS scheme for resharing the evaluation results ofquadraticfunctions on the original secret. We discuss the applications of our DPFSS scheme in distributed systems such as those for health data sharing and smart meter billing. Our scheme is efficient and achieves a communication complexity ofO(n2) and a time complexity ofO(n). Our experimental results show that for a committee of sizen= 100, the communication cost is ≈1.166 MB and the time cost is ≈10.72 s.