On the Design and Security of a Lattice-Based Threshold Secret Sharing Scheme

In this paper, we introduce a method of threshold secret sharing scheme (TSSS) in which secret reconstruction is based on Babai’s nearest plane algorithm. In order to supply secure public channels for transmitting shares to parties, we need to ensure that there are no quantum threats to these channels. A solution to this problem can be utilization of lattice-based cryptosystems for these channels which requires designing lattice-based TSSSs. We investigate the effect of lattice dimension on the security and correctness of the proposed scheme. Moreover, we prove that for a fixed lattice dimension the proposed scheme is asymptotically correct. We also give a quantitative proof of security from information theoretic viewpoint.