The specific encryption method is as follows:
1. Open an arbitrary PDF document;
2. Select "Document" in the menu bar;
3. Select the "Security" column in "Document";
4. Then select the "Show security settings for this document" column in "Security"
5. Enter the "Document Properties" dialog box, click "Security Method" with the mouse, a drop-down menu will appear, and then select "Password Security";
6. Enter the "Password Security—Settings" dialog box, where there are two options to choose from:
a: "Password to open document". If you click in the small box with the mouse, it will be checked, and then you enter your password-confirm. In this way, when someone else clicks on this file, the "Please enter password" dialog box will pop up. If People who don't know the password will not be able to see the contents at all.
b: "Use passwords to restrict the printing and editing of documents and their security settings", if you click in the small box with the mouse, it will be checked, and then you enter your password - Confirm . This will encrypt your current PDF file. When others open your file, they can see its content, but they cannot modify, print, etc.
Set PDF password (This is an official instruction, you can try it.)
You can restrict access to PDFs by setting a password and disabling certain functions (for example, printing and editing).
PDF contains two passwords: "Document Open Password" and "Permission Password". When you set a Document Open Password (also called a "user" password), users must type the password you specify to open the PDF. When you set a Permission Password (also called a "Master" password), recipients can open the document without a password, but they must type the Permission Password to set or change restricted features. If the PDF is protected by both passwords, you can open it with either password, but you must use the Permission Password to change restricted functionality. For higher security, it is better to set two passwords at the same time.
All Adobe products enforce the restrictions set by the License Password. However, because third-party products may not support or ignore these settings, document recipients may bypass some or all of the restrictions you set.
Important Note: If you forget your password, you will not be able to recover it from the document. Please consider keeping a backup copy of the PDF without password protection.
Please do any of the following:
Click the Security button on the Task toolbar and select Remove Security Settings. Type your password, and then click Yes at the prompt about removing security.
In the "Security" tab of the "Document Properties" dialog box, select "No Security Settings" from the "Security Method" menu.
If prompted, enter the License Password and click OK.
PDF is becoming more and more popular in our daily life, and it is very convenient for our work, but sometimes I don’t want to show my PDF files to others. At this time, we need conversion tools. I recommend to everyone the ones I usually use. SanPDF online conversion tool, especially convenient!
The following are the steps to use:
1. Enter the SanP sanPDF homepage and click "Download" to download the client
2. Download and install
3. Installation completed
4.Open the client
5. Click "Select" and select the files you want to encrypt.
6.Set password
7. Click "Encrypt and Save" to save the encrypted PDF file.
8. After completion, click "Open Directory" to browse the encrypted files
But it has limitations:
Unregistered users have 10 conversions and can only convert 2MB files at a time. No downloads allowed Two hour download time limit.
I hope this conversion tool can solve everyone’s troubles~
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