An Information Security Technique Using Steganography

Abstract

This technology proposes a lossless, a reversible, and a combined knowledge activity schemes for cipher text
pictures encrypted by public key cryptosystems with probabilistic and holomorphic properties. Within the lossless theme,
the cipher text pixels are replaced with new values to introduce the extra knowledge into many LSB-planes of cipher text
pixels by multiple layer wet paper writing. Then, the embedded knowledge are often directly extracted from the encrypted
domain and therefore the knowledge embedding operation doesn't have an effect on the secret writing of original
plaintext image. Within the reversible theme, a preprocessing is used to shrink the image bar chart before image coding,
so the modification on encrypted pictures for knowledge embedding won't cause any component oversaturation in
plaintext domain. Though a small distortion is introduced, the embedded knowledge is often extracted and therefore the
original image are often recovered from the directly decrypted image. As a result of the compatibility between the
lossless and reversible schemes, the info embedding operations within the 2 manners are often at the same time
performed in associate degree encrypted image. With the combined technique, a receiver could extract a neighborhood
of embedded knowledge before secret writing, and extract another part of embedded knowledge and recover the first
plaintext image when secret writing.