Protect PDF with Password
Encrypt and password-protect sensitive PDF documents with standard AES-256 bit encryption. Configure user open passwords and administrative permissions restrictions.
Max 50MB • Accepted: .pdf
Passwords do not match
Securing your PDF…
Applying encryption & permissions
Protection Failed
Understanding User vs. Owner Passwords
The PDF standard defines two distinct security layers to regulate how documents are opened and altered. ScanPDF implements both levels according to international PDF encryption specifications.
User / Open Password
Required each time the PDF is opened in any compliant reader. Without this password, document contents and visual pages remain entirely inaccessible.
Owner / Permissions Password
Grants administrative access to alter document permissions, extract pages, or remove password protection. Prevents unauthorized printing or copying even after viewing.
Cryptographic Stream Encryption
Content streams, image objects, and embedded fonts are encrypted at the binary level rather than simply hiding visual layers with cosmetic overlays.
What PDF Protection Controls
Applying a password establishes strict programmatic boundaries recognized by Adobe Acrobat, web browsers, and standard PDF readers.
OPEN ACCESS
- Prompt upon launch
- Blocks unauthorized preview
- Encrypts page streams
- Protects attachments
PRINT CONTROL
- Disables print action
- Restricts high-res print
- Limits paper copies
- Enforces read-only mode
COPY & EXTRACT
- Blocks clipboard copy
- Prevents text harvesting
- Protects embedded images
- Flags permission bitmask
EDIT PREVENTION
- Locks form fields
- Prevents page reorder
- Disables comment adds
- Blocks page deletion
How to Protect a PDF with Password
Secure your document in four easy steps without downloading software.
Select Your PDF File
Upload the unprotected PDF file you want to encrypt.
Set Your Passwords
Type your desired open password and confirm it. Optionally provide an owner password for granular restrictions.
Apply Encryption
ScanPDF processes the document catalogue and encrypts all internal streams with standard algorithms.
Download Protected PDF
Download your secured PDF document. Future viewers will need your password to open the file.
Designed for Confidential Workflows
Add protective locks to sensitive records prior to emailing or uploading to public cloud repositories.
Financial Statements
Protect audits, bank disclosures, tax documents, and payroll summaries
Legal Contracts
Safeguard NDAs, partnership filings, dispute agreements, and deeds
HR & Personnel
Restrain employee reviews, identification records, and medical forms
Intellectual Property
Lock proprietary technical briefs, blueprints, and internal guidelines
Why Use ScanPDF Protect PDF
Native PDF Encryption
ScanPDF utilizes native PDF encryption libraries that comply with ISO 32000 specifications. Password protection is recognized by every major PDF viewer and mobile operating system.
Dual Password Configuration
Specify a viewer password to lock reading access, or configure an owner password to block printing and copying.
Visual & Vector Preservation
Encryption protects the document without altering typography, image resolution, vector line art, or page geometry.
Direct Encrypted Download
Download your locked PDF immediately with all cryptographic permission flags applied.
Important Security Guidance
Protecting a PDF with strong encryption is an irreversible process without the password. Keep these best practices in mind before securing documents.
Encryption Specifications & Permission Boundaries
ScanPDF applies ISO-standard cryptographic protection via PyMuPDF. Here are the exact parameters governing encryption, permissions, and password recovery:
AES-256 Bit Encryption
All internal document streams, catalogues, and metadata are cryptographically locked using standard AES-256 bit encryption (fitz.PDF_ENCRYPT_AES_256).
User & Master Passwords
The User Password is required for opening and viewing. The optional Master Password manages administrative privileges (defaults to User Password if omitted).
Permission Mask Enforcement
Standard printing and screen-reader accessibility are granted, while text extraction, page deletion, annotation addition, and form alterations are restricted.
Technical Questions & Answers
Verified answers regarding PDF encryption mechanics and security boundaries.
What encryption standard does ScanPDF use to protect PDFs?
ScanPDF utilizes AES-256 (256-bit Advanced Encryption Standard) through the PyMuPDF security engine. This is the highest standard encryption supported by the ISO 32000 PDF specification, recognized globally by enterprise and governmental security policies.
What is the difference between the User Password and Master (Owner) Password?
The User Password is the open password required by any recipient to open and read the PDF. The Master Password (owner password) is an administrative credential that allows you to change security settings or remove protection later. If you do not enter a separate Master Password, ScanPDF securely sets it to match your User Password.
What permissions are restricted once the PDF is protected?
By default, ScanPDF locks down text copying, content extraction, page deletion, and annotation editing. Standard document printing and assistive screen-reader access remain enabled so authorized users can still read and print the document.
Can ScanPDF recover my password if I forget it?
No. Because AES-256 encryption is mathematically unbreakable without the key, forgotten passwords cannot be recovered or reset by ScanPDF or any automated tool. We strongly recommend saving your password in a trusted password manager before encrypting sensitive files.