Cryptography Reference
In-Depth Information
Fig. 4.15.
The (2, 5)-VSS scheme on the input image of size 512512.
4.6 Conclusion
A visual secret sharing scheme for gray-scale images is proposed in this chap-
ter. The image is divided into several sectors, and each sector can be used
to hide a secret image. In order to completely recover the original image, the
scheme represents the image by eight planes. The encryption process is then
used to generate shadows for each plane. The scheme then uses the rotation
and reversion operations to rearrange the sectors of each shadow.
In the decryption stage, only the legal participants who own the secret
key needed to generate the random sequences for rearranging the sectors of
the shadows can restore the original image and reveal the secret information.
In addition, if the secret image owner only wants to share only a part of
information with the participants, he can follow the same encryption process
to generate the shadows, and then disperse the sectors, which do not belong
to the participants. In this way, the participants can only retrieve their own
part of the secret information but not the others.
References
1. Chang, C.C. and Chuang, J.C. (2002): An image intellectual property protec-
tion scheme for gray-level images using visual secret sharing strategy. Pattern
