This document must not circulate freely
A PDF forwards in one click: that is its strength and its danger. Three levels of protection exist, and they serve different purposes — an open password prevents reading, a permissions password prevents acting, a watermark prevents nothing but deters and lets you trace a leak.
- You are sending a document with personal data or sensitive figures.
- You want to circulate a draft without it being mistaken for the final version.
- You know a PDF’s password and need to remove it for archiving.
Poulpi’s tip
Never send the password through the same channel as the file: a password in the same email protects nothing. And keep an unprotected copy aside — an encrypted PDF whose password is lost is lost for good.
Linda PDF5 tools
The tools for that
FAQ
Common questions
Open password or permissions password?
The first is required to open the document: without it, you read nothing. The second lets you read but forbids certain actions, typically printing and copying text. You can set both, with different passwords.
Are permissions actually enforced?
They are written into the file and honoured by serious readers, but they are not content encryption. For real confidentiality you need an open password.
Can a PDF password be removed?
Only if you know it: the tool then unlocks the file and hands back a free copy. There is no way around a password you do not have — which is exactly what makes the protection worth anything.
Other needs