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About Protect PDF

Two protection modes. Standard uses AES-256-CBC server-side encryption — set an open password, an owner password, and granular permission flags (print, copy, modify, annotate, form fill, accessibility, assembly). Post-Quantum (PQC) uses client-side quantum-safe encryption with your choice of 31 algorithms — the document is encrypted in your browser using @noble/post-quantum before any data is sent. A key pair or passphrase is generated for you; the private key can be copied or downloaded immediately.

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Drop your PDF here or click to browse

Supports PDF files up to 50 MB

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AES-256 Password Protection — Encrypted with AES-256-CBC (PDF 1.7 standard). Any PDF viewer can open this file with the correct password.

Password to Open PDF

Owner Password (Optional)

Permissions

Allow Printing Allow Copying Text & Images Allow Modifications

🖨️ Printing ✅ Allowed

📋 Copy Text & Images ✅ Allowed

✏️ Modifications ✅ Allowed

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Post-Quantum Cryptography Protection — Your PDF is encrypted using the PQ PDF engine (the same used on this platform). The result is a .pqcpdf bundle that is quantum-computer-resistant. Decrypt it anytime at pqpdf.com.

Protection Method

🗝️ Key-Based (Strongest) Fresh asymmetric PQC keypair generated per file. Save your private key — required for decryption. 🔑 Password-Based (Convenient) Your password is used to derive the encryption key. Easier to share — decrypt with the same password.

PQC Algorithm

Encryption Password

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🗝️ Your Private Decryption Key — Save This Now

⚠️ This key is shown only once and never stored. You need it to decrypt the .pqcpdf file.