MSB/LSB Prediction Based Reversible Data Hiding in Encrypted Images: A Survey

Abstract

Encryption provides security to authentic data that is transmitted from sender to receiver for a particular task. Reversible Data hiding in Encrypted Images (RDHEI) has attained interest as per its assured reliability. The technique make use of secret key to encrypt original image for embedding secret information in it and recuperate original image perfectly with unaltered secret information when extracted. A sort of trade-off persists between embedding capacity and recuperation of original image. Many of the techniques existing in literature use Least Significant Bit (LSB) or Most Significant Bit (MSB) to embed secret information. In plaintext domain, LSB embedding is easy since there is minute change in pixel value of original image which attains less distortion in original image after embedding. Encrypted domain is less restricted than plaintext domain where embedding of secret information can be done either in LSB or MSB. Reason for the previous statement is that after encryption, original image pixel gets evolved as pseudo random numbers and any modification in MSB or LSB are insignificant. This paper reviews prediction error based reversible data hiding (RDH) techniques that too dealing with encrypted domain utilizing MSB or LSB prediction, which enhance the embedding capacity of secret information within original media alongwith it’s full recovery. The encryption of secret information is done either at bit plane level or pixel level.