A (2, 2) Visual Cryptography Technique to Share Two Secrets
Akshay Gajanan Bhosale, Vikram Patil · 2020
Visual Cryptography (VC) is used for sharing secret images. The traditional VC technique is capable of sharing only a single secret. Many researchers have developed techniques for sharing multiple secrets. Most of these techniques use either a circular or cylindrical or ring shaped shares. These shares must be rotated by a specific angle to reveal the secrets. Theoretically, these techniques may give good results but practical implementation of these techniques is tedious. These techniques use ring or cylindrical shaped shares which are difficult to handle. The measurement of the angle by which the share has to be rotated is difficult. In this paper, we have proposed a (2, 2) VC technique capable of sharing two secrets using only two shares. The first secret can be revealed by overlapping both the shares, while for revealing the second secret, we have to flip the second share horizontally and then overlap on the first share. The other advantage of the proposed technique is that the two secret images can have different dimensions, such that the rows and columns of one secret image are less than or equal to the other secret image. The proposed technique is applied on different type of binary images and the quality of recovered secret images is evaluated using different performance metrics.