Only in a original perfect image that has one color, without noise, you are only able to see the encryption:
Try seeing the encryption
[caption id="attachment_1262" align="aligncenter" width="300" caption="Original"][/caption] [caption id="attachment_1263" align="aligncenter" width="300" caption="Encrypted image"][/caption]
You can’t see it? I have amplified the noise for you:
[caption id="attachment_1264" align="aligncenter" width="300" caption="encryption 'noise' amplified"][/caption]
Essentially, what you are looking at are just ones and zeros, which make up our information.
This information can be just text, other images, documents, whatever. And, even if you knew that there was encrypted information in this image, you would have to know how it is implemented. For instance, you can encrypt the information (text) before encrypting it in the image. No way you would ever be able of figuring this out.
Well of course no-one knows who uses this, as that would kind of defeat the purpose of pretending to send an image file but really sending something else inside of that file. You can imagine all kinds of organizations use this for their own causes.
Also, i have read a paper of someone proposing to use this to store copyright information inside of the image; this way his name would be in the ‘noise’ of the image, and only he would have the original. The person that thought of this probably had a bad day, since i could just strip the image of this information by making all the pixels ‘even’ and then imposing my own random noise, making it “my original”. How would you then ever know which was the original?
How do i encrypt my own stuff
I’ll not be helping you with that, ask your local terrorist organization.