I am exploring the protection of PDF in Adobe Acrobact DC Pro. In the document Restrictions summary, I encounter two characteristics as "Content copying" and "Content copying for accessibility". I want to know the difference between these two. Please let me know the difference. Thanks in advance.
32 Answers
The restrictions you specify in PDFs are essentially a form of DRM. While it's true that encryption is used, anybody with a password that lets them read the data at all can trivially copy the data out of the encrypted PDF and into an unencrypted one, letting them copy, modify, and distribute the data freely. Many PDF clients on Linux, for example, don't honor the DRM settings, since anyone could just modify the source code and remove the checks.
As for the two options, the accessibility option lets screen readers and other assistive technologies read the text, but doesn't let people copy it from Adobe Acrobat into another document. Again, this is trivially bypassed, but this provision is required because otherwise encrypted PDFs are totally inaccessible to blind users, which is not only unethical, but also violates the law in many jurisdictions. The option for content copying allows users to copy the contents without restriction regardless of the software that's being used.
None of these options prevent users from copying, modifying, distributing, or printing the full, unedited document if they know the password to read it, so there's no reason to enable any of them, since all enabling them serves to do is irritate legitimate users. A user with pdftk and the password can have an unencrypted PDF in seconds.
When you allow "Content copying for accessibility" feature, this allows reading aloud the text (hearing the text) by the pdf reader software. When you disable this feature, the text can not be heard.
On the other hand, when you allow "Content copying" feature, this allows copying text to be pasted in other location. When you disable this feature, it prevents copying text.
