You can restrict access to a PDF by setting passwords and limiting certain features, such as printing and editing. However, you cannot prevent a PDF file from being saved. Copies have the same restrictions as the original PDF.
There are two types of passwords:
1) Password to open file.A password to open a document (also known as a user password) requires the user to enter a password to open the PDF.
2) Permissions password. The password (also known as the master password) requires a password to change permissions settings. Using a permissions password, you can limit printing, editing, and copying content to PDF. Recipients do not need a password to open the document in Reader or the Acrobat. They need a password to change the restrictions you set. If the PDF is secure with both types of passwords, it can be opened with any password. However, only the password allows the user to change the limited features. Due to the added security, setting both types of passwords is often useful and useful.
How to add a password to a PDF
- Open the PDF in Acrobat DC. Select File> Protect Using Password using your password. Alternatively, you can choose Tools> Protection> Password Protection (Tools> Protect> Protect Using Password). You choose whether you want to set the password to view or edit the PDF.
- You type and re-type your password. The password intensity appears next to your password to indicate whether the selected password is weak, medium, strong or better. Click Apply. Acrobat displays a confirmation message that the file was successfully protected using the password.
How to limit the ability to edit a PDF
You can prevent users from changing PDFs. The edit restriction option prohibits users from editing text, moving objects, or adding fields to a form. Users can still fill in a form's fields, sign or add comments.
- Open the PDF in Acrobat DC and do one of the following: Select File> Protect Using Password using your password. Select Tools> Protection> Password Protection (Tools> Protect> Protect Using Password). If you receive a question, click Yes to change the security. You select Editing, then you type and re-type your password. The password intensity appears next to your password to indicate whether the selected password is weak, medium or strong.
- Click Apply. Acrobat displays a confirmation message that the file was successfully protected using the password.
How to limit printing, editing and copying
You can prevent users from printing, editing, or copying content to a PDF. You can set the restrictions you want to apply to the PDF, which users cannot change unless you give them a password. Illustrator, Photoshop or the InDesign they don't just have view functions. To open a restricted PDF in these applications, the user must enter the permissions password.
- Open the PDF in Acrobat DC and do one of the following:
- Select Tools> Protection> More Options> Password Encryption (Tools> Protect> More Options> Encrypt with Password).
- Select File> Protect Using Password using the password, and then select Advanced Password Protection from More Options.
- If you receive a question, click the "Yes" button to change the security.
- Select "Restrict Editing And Printing Of The Document" ("Restrict Editing And Printing Of The Document").
All its products Adobe impose restrictions on the password. However, if third-party products do not support these settings, document recipients are able to bypass some or all of the restrictions you set.
- Enter the password in the corresponding field. For each keystroke, the password power meter evaluates your password and indicates the password's validity.
- Select what the user can print from the "Print Allowed" menu:
- None: Users are not allowed to print any document.
- Low Resolution (150 dpi): Allows users to print at a resolution not exceeding 150 dpi. Printing may be slower because each page is printed as a bitmap image. This option is only available if Compatibility is set to Acrobat 5 (PDF 1.4) or later.
- High Resolution: Allows users to print at any resolution, directing high quality vector output to PostScript and other printers that support advanced high quality printing capabilities.
- Select what the user can change from the "Changes Allowed" menu: None:
- Users are not allowed to make any changes to the document listed in the "Changes Allowed" menu, such as by filling out form fields and adding comments.
- Insert, Delete, and Rotate Pages: Users are allowed to insert, delete, and rotate pages as well as create bookmarks and thumbnails. This option is only available for high-resolution (128 bit) RC4 or AES encryption.
- Filling in Form Fields and Signing Existing Signature Fields: Users are allowed to fill out forms and add digital signatures. This option does not allow them to add comments or create form fields. This option is only available for high-resolution (128 bit) RC4 or AES encryption. Commenting, filling out form fields and signing existing signature fields: Users are allowed to add comments and digital signatures and to complete forms. This option does not allow users to move page objects or create form fields.
- Anything other than exporting pages: Users are allowed to edit the document, create and fill out form fields and add comments and digital signatures.
- Select any of the following options:
- Enable copy of text, images and other content: Allows users to select and copy the contents of a PDF.
- Enable Text Readers for Visually Impaired Readers: Allows users with visual impairments to read the document with screen readers, but prevents users from copying or extracting document contents. This option is only available for high encryption (128-bit RC4 or AES).
- You select an Acrobat version from the Compatibility menu.
- You select a version equal to or less than the Acrobat or Reader version. The Compatibility option you choose determines the type of encryption used. It is important to select a version compatible with the Acrobat or Recipient Reader version.
- Choose what you want to encrypt:
- Encrypt all document contents: Encrypts the document and the metadata of the document. If this option is checked, the search engines cannot access the document's metadata.
- Encrypt all document content except metadata. It encrypts the contents of a document, but still allows search engines to access the document's metadata.
- Encrypt only attachments: Requires a password to open file attachments. Users can open the document without a password. Use this option to create security folders.
Click the OK button. At the command prompt to confirm the password, re-type the appropriate password in the box and click OK.
You can remove security from an open PDF if you have the rights to do so. If the PDF is secure with a server-based security policy, only the policy maker or server administrator can change it.
- Open the PDF, and then select Tools> Protection> More Options> Remove Security (Tools> Protect> More Options> Remove Security).
Your options vary depending on the type of password security attached to the document:
- If the document only had a password to open the document, click OK to remove it from the document.
- If the document had a permissions password, type it in the Enter Password box, and then click OK. Click the OK button again to confirm the action.