is there such thing as securing/protecting pdf ? like application piracy protection

I saw allot of companies offering开发者_如何学Go exe wrappers , but is there any in pdf side security programmatically ?

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Well, you can encrypt the PDF. You can also use custom encryption handler and thus make your file unreadable with stock Acrobat or Reader (one will need to install your decryption plugin to Acrobat or Reader to make them understand your encryption). The problem is acrobat's DRM SDK (the one that allow you create encryption plugins) once had enormous cost (smth. like $25K to start). I don't know if this is still the case, though.

Another not-so-bad option is render everything to graphics - this makes text copying harder (though one can print everything and OCR it back).

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The short answer is no. When you give someone the ciphertext, key, and cipher they will always be able to reproduce the plaintext. DRM fails universally for just this reason.

The long answer is that you can sometimes try little gimmicky tricks to prevent copying in some circumstances which may "work" if your audience doesn't try breaking it, but not in the general case. You can't really call something secure which is "safe as long as nobody tries to break it".

The PDF format itself has an "owner password" which allows the author to disallow readers from printing the document, modifying it, etc... Of course there's not actually any mechanism for preventing anyone from doing so. If you are trying to prevent the guys in the marketing department from printing it off or something, then maybe. But if you're releasing it out into the Internet, just assume that it can and will be copied however users see fit.