Export & Import Encrypted Files

Qpher Vault lets you create portable encrypted .qpher files that can be transferred offline — via AirDrop, email, USB drive, or any other method. The recipient imports the file into their vault where it's verified and decrypted server-side.

Offline transfer, online decrypt.

Share Encrypted (.qpher)

Send an encrypted copy of your file to another Qpher user:

1. Open the document detail page
2. Tap the menu button, then Share Encrypted

3. Enter the recipient's email address

4. Tap Export Encrypted File — the server creates a .qpher file
5. The iOS Share Sheet appears — send via AirDrop, email, Messages, or save to Files

ℹ️Recipient must have a Qpher account

The recipient needs an active Qpher account to import the file. If they don't have one, the app will suggest using Qpher Share instead (which supports pending shares for new users).

Backup Encrypted

Create a backup copy of your encrypted file:

1. Open the document detail page
2. Tap the menu button, then Backup Encrypted

3. A .qpher file is created with you as the recipient
4. Save it to Files, iCloud Drive, or an external drive

This is useful for creating offline backups that only you can decrypt.

Import a .qpher File

Import a .qpher file you received:

From the app

1. Tap the + button in the document list
2. Select Import .qpher File

3. Select the .qpher file from Files

4. The server verifies the sender's signature, decrypts, and stores the file in your vault

From AirDrop or "Open In"

When you receive a .qpher file via AirDrop or tap one in Files/email, Qpher Vault opens automatically and starts the import process.

Security Properties

Every .qpher file includes multiple layers of security:

Property	Description
Sender Signature	ML-DSA digital signature proves who created the file
Quantum-Safe Encryption	AES-256-GCM + X-Wing KEM encryption
Recipient Binding	Only the intended recipient can decrypt
Header Integrity	AAD binding detects any header tampering
Revocation	Sender can revoke before the recipient imports

🔒Tamper detection

If anyone modifies the .qpher file after export — even a single byte — the import will fail with a signature verification error. This protects against man-in-the-middle attacks.

Import Error Messages

Error	Meaning
Invalid file format	The file is not a valid .qpher file
Sender signature failed	The file may have been tampered with
Share revoked	The sender revoked this export
Already imported	This file was already imported (replay protection)
Share expired	The export has expired
Wrong recipient	This file was encrypted for a different user

Plan Requirements

Plan	PQC-only Export	Hybrid Export	Monthly Limit
Explorer (Free)	-	-	-
Personal	Yes	-	50
Starter	Yes	Yes	50
Professional	Yes	Yes	500

Related Guides

• Share Documents — In-app sharing (no file download needed)
• Access Log — Export and import events appear in your access log