AES-256 open protection
Without the correct open password, the document contents remain encrypted. This is the primary security control.
🛡️ AES-256 output🔐 HTTPS transfer🧹 Temporary-file cleanup🚫 Password not retained
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Drop the PDF you want to protect
or click to select it from your device
Choose PDFPDF only · standard accounts up to 20 MB · premium allowance checked by the serverTwo layers of control
Password encryption and PDF permissions are different
The open password is cryptographic access protection. Permissions tell compatible viewers what an authorized recipient may do after opening the file.
Viewer-enforced permissions
Printing, copying, editing, annotations and forms can be permitted or restricted. Some third-party software may ignore these flags.
Separate owner credential
The server creates a random owner password so the recipient’s open password cannot simply override your chosen restrictions.
Build a safer PDF password
Prefer length
Use at least 12 characters. A memorable multi-word passphrase is often stronger and easier to type than a short complex password.
Keep it unique
Do not reuse an email, banking or workplace password. Store the PDF password in a password manager.
Share separately
Send the locked PDF and its password through different channels when the document is sensitive.
Keep an original
Retain an unencrypted backup in a secure location until you have verified the locked output opens correctly.
How to password-protect a PDF
Upload
Select the PDF you are authorized to protect.
Set access
Create and confirm a strong open password.
Set permissions
Choose permitted actions for compatible readers.
Verify
Download, open with the password and test before sharing.
Frequently asked questions
Which encryption algorithm is used?
The output uses AES-256 encryption through the server’s PDF encryption library.
Can ZeeSharp recover my password?
No. The password is not retained, so there is no recovery mechanism. Keep a secure copy.
Are printing and copying restrictions unbreakable?
No. They are standard PDF permission flags enforced by compatible readers. The open password is the cryptographic protection; permission enforcement varies by software.
Can I protect an already-encrypted PDF?
Yes. Expand the source-password option, provide its current open password, then choose a new output password.
Does locking preserve bookmarks and forms?
The upgraded worker clones the full document structure before encryption to preserve features such as bookmarks, forms, attachments and page labels more reliably.