Please provide me the code for reversible data hiding in encrypted images by reserving room before encryption

please help me how to find the smooth area and how to convert the texture format and rearrange the image pixel value using LSB

Answer 1

[Image Analyst]

That's not a built-in function of MATLAB. You'll have to write it yourself. To find smooth areas, you can use stdfilt() or entropyfilt(). If you want an example of LSB watermarking, see my attached demo.

[JYOTHY JACOB]

Usually we are doing encryption first and then datahiding. Is it possible to hide data first and then encrypt. Is there any logical issues?

[Walter Roberson]

There are a few different possibilities:

• encrypt data and hide that in visible image. result looks like regular image. If someone happens to know the same sequence of locations to extract from they get encrypted data. But you could use the same set of locations with multiple sets of data: both would have to be discovered by attackers to get the data
• hide unencrypted data in image and encrypt the result. This would obviously be non-image so people would know to investigate. Finding data hiding algorithm is probably easier than finding encryption, so if encryption leaks chances increase that all files can be interpreted. People able to find encryption are going to see the ordinary picture and are not likely to be satisfied that that is all there is to the file. More suspicious than above# encrypt image and hide the unencrypted data in the result. This has the same power as just taking random data and hiding something in it. Yes, you could waste a bunch of the attacker's time trying to decrypt the file when that is not needed. Decryption might not be possible because of the effects of hiding the data in the encrypted file. Not useful for sending actual images then.

Any of these can be done, but encrypting the data and hiding that is probably the most useful.