Hallo Herr Rohrfrei,
danke für Ihre Antwort. Das ist die Antwort von Adobe. Muss sie aber erst noch übersetzen und ausprobieren. Mein Englisch ist nicht so gut.
Use security settings in Acrobat (6.x - 7.x on Windows and Mac OS)
What's covered
RC4 encoding
Secure a PDF file in Acrobat
Catalog and secured PDF files
You can restrict access to an Adobe PDF file by saving it in Adobe Acrobat with password security. You can set a password that restricts others from opening the PDF file without the password, set a password that restricts functions (for example, printing, opening, or selecting text) and that restricts others from changing the security options you selected, or both. When you set passwords for both security options, you should use different passwords; otherwise, anyone who opens the file can remove the restrictions.
RC4 encoding
Acrobat uses the RC4 encoding method, developed by RSA Corporation, to secure PDF files. Acrobat uses 128-bit RC4 encryption (the maximum level permitted by federal regulations at the time of this writing).
The RC4 encoding method meets federal regulations. If legal issues are encountered as a result of distributing secured PDF files, the resolution of these issues is the responsibility of the author or distributor of the PDF files, not of Adobe Systems Incorporated.
Secure a PDF File in Acrobat
You set security passwords and restrictions from within the Password Security-Settings dialog box.
To set security passwords and restrictions:
1. Open the PDF file, and choose Document > Security > Restrict Opening And Editing.
2. Choose a compatibility option from the Compatibility menu.
3. Do one or both of the following tasks:
-- If you want to require a password to open the document, select Require A Password To Open The Document, and then enter a password in the Document Open Password box.
-- If you want to restrict permissions within the document, do the following procedure:
a. Select Use A Password To Restrict Printing And Editing Of The Document And Its Security Settings, and then enter a password in the Permissions Password box.
b. Choose a setting from the Printing Allowed menu.
c. Choose a setting from the Changes Allowed menu.
d. Select the permissions you want to enable from the available options. (Certain options may or may not be available depending on the Compatibility option you chose in step 2.)
4. Click OK.
5. Save the file.
Catalog and secured PDF files
The Catalog feature in Acrobat cannot index PDF files to which you have applied password security. Before Catalog can index a PDF file, it must first open the file, and in some cases add a unique identifying code. Because Catalog cannot enter a password before opening a PDF file, it cannot perform the functions required to index the file. When you attempt to index a PDF file that has security applied, Catalog returns the message "Could not open document - Document requires an Open password: [filename]." Although Catalog continues to build the index, it doesn't include the password-protected document.
You can remove the password security from a PDF file if you're the author of the file, or if you know the Change Security Options password(s).
To remove the password security for indexing:
1. Open the PDF file.
2. Choose File > Document Properties.
3. In the Document Properties dialog box, choose Security in the left pane.
4. Choose No Security from the Security Method menu.
5. Click OK.
6. Choose File > Save As to save the PDF file, and then index the file again.
als Antwort auf: [#274010]