An efficient lossless (2, n) secret image sharing based on Blakley's scheme

摘要

Visual Secret Sharing (VSS) is a type of cryptographic method used to secure digital media such as images by splitting it into n shares. Then, with k or more shares, the secret media can be reconstructed. Without the required number of shares, they are totally useless individually. The purpose of secret sharing methods is to reinforce the cryptographic approach from different points of failure as a single information-container. Instead of Lagrange's interpolation employed by classical methods, an approach based on linear equations and coding theory resolves the classic problems of VSS methods like pixel expansion and information losses at recovery time. In this paper, we propose an efficient (2, n) secret image sharing scheme without loss of information and size increase of shares, with n ≤ 7 based on linear equations encoded into eight bits to encode separately pixels and permutations to maintain high entropy in shares.