Sharing two true colour images using (3, 3)-extended visual cryptography technique

ABSTRACT

In this work, a (3, 3)-extended visual cryptography technique to share two true colour secret images is proposed. Three meaningful shares are created using two different components of the colour images. Each pixel of the original cover image is expanded into a $5\times 5$ block. The positions of RGB components of the secret images are decided by two logic matrices which are selected at random during the encryption process. The generated shares are embedded into expanded blocks of the cover image to make them meaningful. These meaningful shares are more secure than random noisy images as they avoid suspense. To reconstruct the secret images on receiver side, all three shares are required. Proposed technique reconstructs the original image without any data loss and contrast. The dimensions of secret images, cover images and reconstructed images are same. To show its effectiveness, proposed technique is compared with state-of-art existing techniques.

KEYWORDS:

• Secret sharing
• visual cryptography technique
• extended visual cryptography technique
• RGB decomposition
• true colour image

Disclosure statement

No potential conflict of interest was reported by the authors.