Hello everybody.
I meeting you new. I want make the some project about stegenografi in C#. Actually i want preserve some message in picture with the kriptografi like a RSA etc.
How can do u help me for the find the document

Time to do some web searching I think. These are well-known subjects and there is a lot of information out there, but in any case, you need to understand at least three subjects quite well.

  1. Image processing.
  2. Cryptography
  3. Steganography.

The last could be considered a branch of image processing (#1), but there are nuances that must be considered as a separate subject.

So, I think that this is not the forum you need for real help with this subject, although I'm sure there are folks here who know quite a bit about these subjects. Myself, I know quite a bit about cryptography, a fair bit about image processing, and steganography only in theory.