You can protect your documents from being read or saved by unauthorized persons by applying document protection – or more specifically, read and/or write protection. For example, you can require the entry of a password to open or save a protected document.
Read protection also encrypts the document so that it cannot be viewed with programs other than Presentations.
To protect a document, proceed as follows:
| 1. | Choose the ribbon command File | group File management | Properties  . |
| 2. | Switch to the Protection tab. |
| 3. | Select the desired type of document protection (see below). |
| 4. | Enter the read and/or write password (between 4 and 15 characters). |
Important: If you forget a password, you can no longer open or save the document. It is thus advisable to make a note of the password. Pay close attention to uppercase/lowercase!
| 6. | The program displays a dialog box in which you are required to verify the read and/or write password by re-entering it. |
| 8. | Exit the dialog box with OK. |
| 9. | Save the document in order for the changes to take effect. |
From now on, anyone who attempts to open this document will be asked automatically for the password. If the correct password is entered, the protection is temporarily overridden.
Types of document protection
You can choose between the following types of document protection in the above dialog box:
▪No protection
| The document is not protected. This is the default setting. |
▪Write protection
| When the document is opened, the user is prompted to enter the write password. The document can only be saved if the correct write password has been entered here. |
| However, it is still possible to open the document as read-only, even if the user does not have the password. However, it cannot be saved – not even under a different name. |
▪Read protection
| If you try to open the document, you are prompted to enter the read password. If you enter an incorrect password, you will not be able to open the document. |
| The document is saved in an encrypted form so that it cannot be viewed with programs other than Presentations. |
▪Protection depending on password
| Here, two dialog boxes prompting for a password appear in succession when the document is opened. The first dialog box asks for the read password, while the second one asks for the write password. |
| If the user enters the read password, he is permitted to open the document but not to save it. |
| If he also enters the write password, he has full access and can thus save the document. |
| If you enter an incorrect password or nothing at all, access to the document is completely denied. |
Encryption method: "Most compatible" or "Most secure"?
For documents with Read protection or Protection depending on password, you can also select the desired Encryption method.
Note: This setting primarily affects newly created documents. When you open an existing encrypted document, the encryption method used in it is automatically determined and this option is set accordingly.
Choosing an encryption method is especially important for documents in Microsoft PowerPoint file format (.ppt and .pptx). Some old versions of Microsoft Office may not be able to open documents encrypted with the new "Most secure" encryption method.
Available options:
▪Most compatible
| When you save the document, an old encryption method is used that can be read by all versions of Microsoft Office. However, this method is less secure than the other method. |
▪Most secure
| Here, a more modern and more secure encryption method is used. However, some old versions of Microsoft Office may not be able to read documents encrypted with this method. |
Detailed information about the currently selected encryption method is displayed at the bottom of the dialog box.