Data over camera
One screen displays encoded frames; the other camera captures them.
The sending device animates a sequence of QR-code tiles on its screen. The receiving device holds its camera facing the screen and reassembles the payload tile by tile. Throughput is around one megabyte per minute at room distance, and a single transfer can carry up to roughly six megabytes of arbitrary binary data or plain text up to 4096 characters per send. AES-256 encryption can be applied to the payload before the tiles are generated.
- Highest payload of any channel: any small file (PDF, photo, key bundle, signed transaction) up to about six megabytes per session.
- Throughput around one megabyte per minute at typical room distance.
- Completely silent. Works across a counter, window or glass partition where handing over the device is not possible.
- Line of sight only. Range is roughly 5 centimetres to 1 metre depending on screen size and lighting.
- Does not pass through a wall, around a corner, or when only one party can hear (use the Sound channel for those).
Any payload larger than a few words. Best for files. Anywhere the receiver can point a camera at the sender's screen.
Two devices. One shared password. No intermediary.
Install Taftan on both devices, agree on the password through a separate channel beforehand, and run a quick test transfer using whichever channel fits your situation.