A Lock and Key Share (2, m, n) Random Grid Visual Secret Sharing Scheme with XOR and OR Decryptions

Security of secret sharing schemes has become a significant issue as secret communication is now being widely used. Random grid based visual secret sharing (RG-VSS) schemes has drawn greater attention taking into consideration its own specific advantages. A (2, n) RG-VSS produces n shares with equal priorities and any of those two shares can be combined to restore the original image. The proposed system boosts the security of (2, n) RG-VSS by integrating a lock and key share concept. A lock and key share (2, m, n) scheme generates m lock and n key shares, and retrieval of original secret is possible if and only if one share is selected from the set of m lock shares and other from the set of n key shares. Both OR-based and XOR-based decryptions are implemented. Further, necessary theoretical proofs are supplied for the correctness of the implementation.