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View & Decrypt

You can view your encrypted files directly in the app. Decryption happens server-side — the private key never touches your device.

View an Encrypted File​

  1. Tap on any document in your document list
  2. On the document detail page, tap View
  1. The file is decrypted server-side and streamed to the viewer
  1. The file preview appears — you can pinch to zoom, scroll, and navigate
Supported preview formats

The viewer supports images (JPEG, PNG, HEIC), PDFs, and text files. Other file types can be saved to your device and opened with the appropriate app.

Save the Original File​

To save the decrypted file to your device:

  1. Tap the menu button (three dots)
  2. Select Export to Files
  1. Choose a location in the Files app
  2. The decrypted file is saved
Security notice

When you save the decrypted file to your device, it is no longer protected by Qpher encryption. A copy of the encrypted version remains safely in your vault.

How Decryption Works​

When you view a file, the following happens behind the scenes:

  1. The encrypted file is downloaded from secure storage
  2. The wrapped DEK is sent to the server-side KMS
  3. The KMS unwraps the DEK using the private key (which never leaves the KMS)
  4. The file is decrypted with the unwrapped DEK
  5. The decrypted content is streamed to your device
  6. The DEK is securely erased from memory

Watermarks​

If you're viewing a shared file from an organization, a watermark may be applied based on the organization's security policy. The watermark shows your email and the current date to discourage unauthorized sharing.