Problem

A family member needs a working VPN address before the end of the evening. All messaging apps are offline. There is a printed reference sheet and a phone in hand.

With Taftan

The address is entered into Taftan, the acoustic channel is selected, a shared password is set and the device plays the signal. The receiving device, sitting two metres away on the table, decodes it.

Outcome

The address is received in under a minute. No SIM card contacted the network. No server logged anything. The two devices handled the exchange entirely on their own.

Problem

A wallet seed phrase needs to be shared. The only working messaging app scans every photo and message for content flagged by the platform operator.

With Taftan

An existing photo is selected, the steganographic channel is opened, the seed phrase is pasted in, a password is set and Taftan produces a new photo that is visually identical to the original. The photo is sent through the messaging app.

Outcome

The receiving party opens the photo in Taftan, enters the password and the seed phrase is there. The messaging app received only a photo. The seed phrase was never exposed.

Problem

A hardware signing device is kept offline intentionally. A transaction needs to go in and a signed transaction needs to come out, with no network connection at any point.

With Taftan

Taftan on the online device displays an optical frame grid. The offline device captures it with the camera. The offline device then displays its own frame grid in response. The online device records it.

Outcome

Data crossed the air gap in both directions. The offline device stayed disconnected from every network throughout.