Improvement of the Algorithm to Evaluate Security Strength of Share Assignment on Communication Network in SSS

We propose a new algorithm for the share assignment problem, which evaluates how the security strength varies depending on where shares are stored on a communication network in the secret sharing scheme. For a long time, the secret sharing scheme was studied only in terms of how to make shares. However, a recent study indicated that the security strength depends on where shares are stored on the communications network after they have been made and proposed a method for evaluating the security strength of each allocation of shares. However, the algorithm of the proposed method is inefficient. Here, we propose an improved algorithm based on a binary tree search. Numerical experiments show that the presented method surely reduces the computer usage time compared with the original method.