Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method
Kuang Tsan Lin, Sheng Lih Yeh · Mathematical Problems in Engineering · 2014
The Rivest‐Shamir‐Adleman (RSA) encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot‐matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot‐matrix holographic image. The pixels of the dot‐matrix holographic image contain seven groups of codes used for reconstructing the covert image. The seven groups of codes are identification codes, covert‐image dimension codes, covert‐image graylevel codes, pre‐RSA bit number codes, RSA key codes, post‐RSA bit number codes, and information codes. The reconstructed covert image derived from the dot‐matrix holographic image and the original covert image are exactly the same.