Lock PDF

Secure your PDF documentation with banking-grade AES-256 encryption.

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Drag & Drop PDF files

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Table of Contents

Lock PDF - Encrypt Files Online

Protect your sensitive documents with a password. Prevent unauthorized access, copying, or printing.

1

Upload PDF

Select the PDF file you want to protect. Drag & drop is supported.

2

Set Password

Enter a strong password. You can also set a separate admin password.

3

Encrypt & Save

We process the file instantly. Download your secured PDF immediately.

Pro Tip: Dual Passwords

For maximum control, use an "Owner Password" different from the "User Password". This allows you to give someone read-only access (via User Password) while keeping editing rights for yourself (via Owner Password).

Security Suite

Unbreakable Encryption

We use standard cryptographic protocols to ensure your document remains safe on any device.

Strong Encryption

Encrypts the entire document structure with a 256-bit key, making unauthorized access impossible.

Copy Protection

Disable content copying to prevent users from easily extracting your text or images.

Print Restriction

Prevent printing entirely or allow only low-resolution printing for draft purposes.

Smart Metadata

Optionally encrypt metadata so even search engines cannot read the title or author.

RiseConvert Difference
FeatureBasic ToolsRiseConvert
Encryption Strength128-bit RC4 (Weak)256-bit AES (R6)
ProcessingOften saves copyMemory only
Permission ControlBasic LockGranular (Print/Copy)
CostFreemium100% Free

Secure Everything

Essential security for personal and professional documents.

Legal Documents

  • Protect client contracts
  • Secure NDAs
  • Disable text copying

HR Records

  • Encrypt employee data
  • Safe email transfer
  • Compliance ready

E-Books

  • Prevent distribution
  • Stop printing
  • Protect IP

Trusted Security

Thousands of users trust our encryption daily.

"I need to send contracts safely. This tool is quick and lets me stop people from editing the files I send."

E
Elena R.
Legal Assistant

"Perfect for protecting my invoices. I like that I can password protect opening it."

M
Mark T.
Freelancer

"Simple, fast, and secure. Exactly what I need for sharing preliminary data."

D
Dr. Chen
Researcher
Cryptography Core

Military-Grade Defense.
Zero Compromise.

Security is binary: it's either uncrackable or it's broken. We chose uncrackable.

Our locking engine utilizes AES-256 (Revision 6) encryption. This is the same standard used by governments and banking institutions worldwide. When you set a password, we generate a 256-bit key that is chemically impossible to brute-force with current computing power.

We also implement Granular Permissions. Beyond just opening the file, our engine manipulates the PDF's internal permission flags (bitmasking), allowing you to specifically disable printing, copying content, or modifying annotations, giving you total control over your document's lifecycle.

256
SHA
TLS
Secured by Cryptography Experts

AES-256

The highest standard for PDF encryption available today.

R6 Handler

Uses Revision 6 handlers to ensure modern compatibility.

Ephemeral Keys

Encryption keys exist only in RAM during processing.

Understanding PDF Encryption

PDF security isn't just about a password; it's about encryption algorithms. When you lock a PDF with RiseConvert, the entire file body (objects, streams, and cross-reference tables) is scrambled using the AES-256 algorithm.

The "key" to unscramble this mess is derived from your password using a complex hashing function (SHA-256) iterated thousands of times. This makes "brute-force" attacks (trying every password) computationally infeasible. Additionally, the permissions system allows the file to be readable by anyone but restricts specific operations like modifying the text or extracting images, enforcing digital rights management directly within the file syntax.

Security Glossary

AES-256

Advanced Encryption Standard with a 256-bit key. The current gold standard for data security.

Owner Password

Also known as the Master Password. Used to change permissions or unlock the file without restrictions.

User Password

The password required merely to open and view the document.

Encryption Key

A mathematical value that determines how the data is scrambled. Generated from your password.

Frequently Asked Questions

Privacy-First Architecture

Your Secrets.
Stay Yours.

We operate on a strict volatile-memory basis. We don't store your files; we process and forget them.

Auto-Wipe

Files are automatically purged from our servers 2 hours after your session.

TLS 1.3 Encryption

All transfers are secured with the highest standard of web encryption.

Live Security Specs
AES-256
Encryption Standard
100%
Automated Cleanup
"Security isn't an option. It's the default."