Symmetric key based blocked oriented digital enveloping

Digital enveloping is the process of embedding information into a digital multimedia object which is used to protect information, and conceal secrets. In digital enveloping, concentration in given on the retrieval of the original data enveloped within another media. In this current work we have proposed a technique called block oriented digital enveloping where an image as secret is enveloped within another image. Here the cover image is divided into blocks and the blocks are chosen based on a pseudo random sequence generated by a symmetric key. For testing, the paper presents 2 types of bit replacing and performs various quality measures of the enveloped image.