Advanced Steganographic Approach for Hiding Encrypted Secret Message in LSB, LSB+1, LSB+2 and LSB+3 Bits in Non standard Cover Files

In digital steganography normally image, audio or video files are the standard cover files or the host files for embedding secret message such as text, image, audio or video. Nath et al.(2) explored the standard method for hiding secret message inside standard cover files such as image, audio or video files. In the present work we have shown how we can hide secret message in encrypted form in some non standard cover files such as .exe, .com, .pdf, .doc, .xls, .mdb, .ppt files. However, the size of the secret message must be very small in comparison to cover file. The secret message is converted to encrypted form using MSA algorithm(2) and then we hide the encrypted message inside the non standard cover file. To hide encrypted secret message we insert the 8 bits in 2 consecutive bytes of cover file in LSB, LSB+1, LSB+2 and LSB+3 positions. This method could be very effective to hide some information in some executable file. To make the entire process secured we have introduced the password when we hide message and while encrypting the secret message we have to input some text_key. While hiding secret message in cover file we embed 1 byte information in two consecutive bytes of the cover file. There is a risk factor that it may damage the cover file in such a way that the embedded cover file may not behave in proper way as it was behaving before insertion of secret message. However, there is one advantage that we can embed more data in a cover file. We propose that our new method could be most appropriate for hiding any file in any non-standard cover file such as executable file such as .EXE or .COM file, compiler, MS-Office files, Data Base files such as .MDB, .PDF file. Our method will now give open challenge to all user that it is possible to hide any small secret message inside in any non standard cover files. The present work shows that we can hide information in almost all files except pure text or ASCII file. The only restriction is the size of secret message should be extremely small in comparison to cover file. The present method may be implemented in digital water marking in any legal electronic documents, Bank data transactions, in government sectors, in defense, in schools and colleges.