A framework for counting based secret sharing scheme for images

The existing secret sharing schemes used to protect sensitive multimedia data in distributed forms often compromise either security or computational overhead. To address this issue, a counting-based secret sharing scheme has been introduced that reduces the complexity of the algorithm with less computational overhead and also provides perfect security. However, existing counting-based secret sharing schemes have not been developed for multimedia data such as images and videos. This paper introduces a framework for a counting-based secret image sharing scheme. The proposed scheme is a perfect ( n , n ) type, where the first n denotes the number of shares distributed, and the second n signifies the number of shares required to reconstruct the secret image, thus providing perfect security. Here, ‘counting’ refers to counting the number of bits’ occurrences. The proposed approach is divided into two processes: share generation and secret reconstruction. In the share generation process, lightweight horizontal bit counting combined with bitwise additive modulo operations are used to generate the n randomized shares from one secret image and n - 1 arbitrary images. The arbitrary images increase the randomness in the shares, which enhances security. In the secret reconstruction process, all n shares are required to recover the secret, demonstrating the scheme’s perfect secrecy. The secret reconstruction process utilizes lightweight horizontal bit counting. Both the share generation and secret reconstruction processes employ lightweight horizontal bit counting and bitwise additive modulo operations to reduce the overall computational overhead. The approach has been tested on both grayscale and colored images, each with a resolution of 512 × 512 pixels, demonstrating its adaptability to various types of multimedia images. Its effectiveness has been validated through rigorous statistical analysis, including tests for correlation, RMSE, PSNR, SSIM, NPCR, and UACI, all of which indicate superior performance compared to existing schemes. Histogram analysis of the shares further confirms their high randomization and the secure non-disclosure of secret information. The comparison of parameters with existing work shows that our approach outperforms them. However, the primary limitation of this scheme is that it is designed to secure only a single secret and does not support multiple secrets. Moreover, the absence of fault tolerance highlights the scheme’s emphasis on perf