Add a password to a pdf – Adobe Acrobat XI User Manual
Page 361
354
Security
Last updated 1/14/2015
If the PDF is secured with both types of passwords, it can be opened with either password. However, only the
permissions password allows the user to change the restricted features. Because of the added security, setting both types
of passwords is often beneficial.
Note: You cannot add passwords to a signed or certified document.
Add a password to a PDF
You can add password security to a PDF. To open the PDF, the user must enter a password.
1
Open the PDF and choose Tools > Protection > Encrypt > Encrypt with Password. (If the Protection panel is not
visible, choose View > Tools > Protection.)
To apply protection to a PDF Portfolio, first open the PDF Portfolio and choose View > Portfolio > Cover Sheet.
Then choose Tools > Protection > Encrypt > Encrypt With Password.
Note: If these options are unavailable, it’s either because the document or PDF Portfolio already includes security
settings, was signed with a certificate-based signature, or was created in LiveCycle Designer ES.
2
If you receive a prompt, click Yes to change the security.
3
Select Require A Password To Open The Document, then type the password in the corresponding field. For each
keystroke, the password strength meter evaluates your password and indicates the password strength using color
patterns.
4
Select an Acrobat version from the Compatibility menu. Choose a version equal to or lower than the recipients’
version of Acrobat or Reader. The Compatibility option you choose determines the type of encryption used. It is
important to choose a version compatible with the recipient's version of Acrobat or Reader. For example, Acrobat 7
cannot open a PDF encrypted for Acrobat X and later.
• Acrobat 6.0 And Later (PDF 1.5) encrypts the document using 128-bit RC4.
• Acrobat 7.0 And Later (PDF 1.6) encrypts the document using the AES encryption algorithm with a 128-bit key
size.
• Acrobat X And Later (PDF 1.7) encrypts the document using 256-bit AES. To apply 256-bit AES encryption to
documents created in Acrobat 8 and 9, select Acrobat X And Later.
5
Select an encryption option:
Encrypt All Document Contents
Encrypts the document and the document metadata. If this option is selected,
search engines cannot access the document metadata.