Invented by Adobe Systems and perfected over 17 years, PDF （Portable Document Format ) have become as commonplace as MS office files. As the global standard for capturing and reviewing rich information from almost any application on any computer system, it is almost used by anyone, anywhere. Sometimes PDF files contain sensitive information, to protect the files from unauthorized users, you may need to encrypt them. Go on reading to find out how to protect your PDF files by add password for PDF files with 40 or 128 bit encryption via a document converter like VeryPDF docPrint Pro:
- First run VeryPDF docPrint Pro.
- Go to drag the PDF files you want to encrypt to the interface of VeryPDF docPrint Pro.
3. Now go to the click Setting button in the interface above to open the Setting dialog box as illustrated as following.
4 select PDF Security on the dialog box as illustrated above, the box will change to the following dialog box as following.
- Go to select Encrypt Password, the words will turn from gray to black.
- >type passwords in the User Password and the Master Password edit boxes respectively.
- >Select Encryption Level as either 40-bit RC4 or 128 RC4 by clicking the small button.
- >Choose one of the four Permission options to protect your PDF files form being printed, copied or changed by others.
- >Next, click OK to save the setting and close this dialog box.
Then, it will go back to the first interface as illustrated above.
5 Click Start and save the outputting PDF file. After several seconds, Adobe will try to open the PDF file and prompt you for a password.