Password Protecting PDF Documents
Enable password protection for a PDF document to either limit access to the whole document, or to restrict what can be done with the document.
Accessing Security Settings
To access and review a PDF document's security settings, choose File 
Document Properties and click the Security tab.
You will find information about all Document Security and encryption settings, as well as Document Restrictions that were chosen by the document's original author.
Setting a Password Required to Open a Document
Choose File Document Properties and click the Security tab. If no document security has been configured on this document before, click Set Password & Restrictions. If document security had been defined by you or the original document author previously, click Modify Password & Restrictions. Only one of both options will be available. If restrictions have been defined before, you will be prompted for the password to modify those restrictions (the "owner password").
To password protect a document, check the Require password to open the document option. Enter a password and repeat the same password in the field below and click OK to apply your changes.
Your new settings will be applied to the document when you save the document. The next time you open this document, either in PDF Annotator, or in another PDF application, you will be prompted to enter the password you defined above in order to open and view or print the document.
Restrict Editing and Printing a Document
Choose File Document Properties and click the Security tab. If no document security has been configured on this document before, click Set Password & Restrictions. If document security had been defined by you or the original document author previously, click Modify Password & Restrictions. Only one of both options will be available. If restrictions have been defined before, you will be prompted for the password to change those restrictions (the "owner password").
To restrict what can be done with the document, check the Restrict editing and printing the document option. This will completely disallow editing and printing the document, with some exceptions to be defined in the following options: Allow editing, Allow printing, Allow copying of text, images and other content and Allow text access for screen reader devices for visually impaired. Some of these options provide another sub-option to define in even more detail what you want to allow and disallow. Enter a Password and repeat the same password in the field below. This password, also known as the "owner password", will be required to modify or remove the restrictions set above, or to open the document without restrictions. Click OK to apply your changes.
Your new settings will be applied to the document when you save the document. The next time you open this document, either in PDF Annotator, or in another PDF application, all editing and printing actions, except the ones you allowed above, will be unavailable. Changes to restrictions will be applied the next time you open the document.
 | Remember that if you want to add annotations to a PDF document in PDF Annotator, either commenting or editing has to be allowed for the document. |
Choosing a Security Level
Setting a password or defining restrictions implies that the PDF document will be encrypted to avoid unauthorized access to the document. Set the Security Level by selecting a Compatibility option when defining password and restrictions. A higher security level will give you more security by using stronger encryption. Older versions of PDF readers did not support those strong encryption standards yet, and will not be able to open or process documents with any security level. If compatibility is more important than security, we suggest to use at least a security level of 128-bit AES, which is supported by Adobe 7 and later. For maximum security, we suggest a security level of 256-bit AES, supported by Adobe X and later.
Removing Password and Restrictions from a Document
Choose File Document Properties and click the Security tab. Click Remove. This button will only be available if document security had been defined by you or the original document author previously. If restrictions had been defined, in order to remove those, you will be prompted for the password to change those restrictions, also known as the "owner password". Click OK to apply your changes.
Your new settings will be applied to the document when you save the document. Changes to restrictions will be applied the next time you open the document.
See also
