Improved secret image sharing scheme with payload optimization

This paper presents an improvement of interpolation-based (k,n)-threshold secret image sharing (SIS) scheme, where a secret data payload is optimized using Lagrange Interpolation operated in GF(2⁸). A secret data can be not only images but also any type of files, such as documents and executable files, which is hidden using Least Significant Bit (LSB) steganography into n innocent-looking images called camouflage images. In order to recover the secret data, at least k (≤n) camouflage images are required. The proposed scheme provides an authentication mechanism by parity-bit checking and lossless recovery of the secret data using GF(2⁸) operation. Controlling the value of k, the size of camouflage images can be controlled to avoid a pixel expansion occurred in conventional SIS schemes.