XOR-based visual secret sharing scheme using pixel vectorization

The XOR operation has improved the recovery effect of the visual secret sharing schemes. Various visual secret sharing schemes based on XOR operation are available in the literature with some limitations, e.g. direct non-applicability of the scheme to the gray-scale images and reduced quality of the reconstructed secret image. Many existing visual secret sharing schemes in the literature, firstly converts grayscale secret image into a halftone image then creates the shares. This paper proposes XOR-based (n,n) - VCSXOR visual secret sharing scheme using pixel vectorization. It diffuses and disguise secret information into multiple meaningless shares prior to allocating participants of the group having no clue about the secret information. The scheme also resolves various problems like pixel expansion, contrast-loss, explicit codebook requirement, limitation on number of participants and lossy recovery of the secret image. The proposed scheme makes use of implicit codebook and pixel vectorization to encode gray secret image directly without converting to halftone image, into multiple random looking shares. Also applicable to binary image. Reveal a secret image perfectly by XOR-ing all share. The efficacy of the proposed scheme is verified by numerical illustrations, experimental results and comparative analysis. We found that proposed scheme outperform in comparison to the state-of-the-art approaches.