How PrintGuard Works
PrintGuard uses browser-side encryption to ensure your document is never readable by the server, the network, or the print shop's computer. Here is the full process, step by step.
Choose your file and passphrase
Select any PDF or image file from your device. Enter a passphrase — this is the only key that can decrypt your document. It never leaves your browser.
Encryption happens in your browser
Before any data is sent to the server, your browser encrypts the file using AES-256-GCM. The passphrase is processed through PBKDF2 (600,000 iterations) to derive the encryption key. This happens entirely on your device.
Encrypted blob is uploaded
Only the encrypted, unreadable version of your file is sent to PrintGuard's servers. No server or person at PrintGuard can read it — we receive ciphertext, never your document.
You receive a print code
You get a unique job code (e.g. WORD-1234). Share this code with your print shop verbally or by showing your screen. Then separately tell them the passphrase — also verbally.
Shop decrypts and prints
The print shop enters the job code on their screen. Their browser fetches the encrypted blob, and using the passphrase you provide, decrypts the document locally. It never touches their disk.
Automatic deletion
Once printing is confirmed, the encrypted file is permanently deleted from the server. Even if someone tried to download it afterwards, there is nothing left to find. Files also auto-delete after one hour if printing never happens.
Frequently asked questions
Is my file stored on the server?▾
Yes, but only in encrypted form. Without your passphrase it is completely unreadable. The server never sees the plaintext.
What happens if I forget the passphrase?▾
There is no recovery. The passphrase is the only key. This is a deliberate security design — it means no third party can ever retrieve your document for you or anyone else.
Can I use PrintGuard without an account?▾
Yes. No account, no email, no phone number is required. We do not collect any personal information during normal use.
How long is my file kept on the server?▾
Files are deleted immediately after printing is confirmed, or automatically after one hour if printing does not happen.
What file types are supported?▾
PDFs and common image formats (JPG, PNG, TIFF). The viewer is rendered in the browser, so no software installation is needed at the print shop.
Is the connection to the server secure?▾
Yes. All communication uses HTTPS. Additionally, the file is encrypted client-side before upload, so HTTPS provides a second layer of protection, not the only one.