Question 1

Is this real encryption, or just a weak lock?

Accepted Answer

Real encryption. We apply genuine AES-256 — the same cipher standard Acrobat and other professional tools use — entirely in your browser. It’s not a flimsy “permissions only” lock or weak legacy RC4. After protecting, the PDF genuinely can’t be opened without the password.

Question 2

Is my file uploaded to encrypt it?

Accepted Answer

No. The encryption runs entirely on your device — your PDF and your password are never uploaded, stored, or seen by us.

Question 3

How strong is the protection?

Accepted Answer

The cipher is AES-256, which is not breakable by brute force. In practice the protection is only as strong as your password — a short, common password can be guessed, so choose a long, unique one. The strength meter helps you pick a good one.

Question 4

What’s the technical detail, honestly?

Accepted Answer

We use the AES-256 (AESV3) standard security handler via @cantoo/pdf-lib, a maintained open-source pdf-lib fork, with the encryption keys and salts generated by your browser’s secure random generator. It’s a standard algorithm implemented by a community library (not a separately audited crypto product). For most everyday protection this is solid; for high-stakes legal or regulatory needs, use a vetted enterprise tool.

Question 5

What if I forget the password?

Accepted Answer

There’s no recovery or back door — that’s the point of real encryption. If you lose the password, the file can’t be opened. Store it somewhere safe, like a password manager.

Question 6

Can I protect a PDF that’s already password-protected?

Accepted Answer

Not directly — unlock it first (with the Unlock PDF tool and its current password), then protect it again with the new password.

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