How it works
A screen, a camera, and two signatures.
Kionel moves a file between two devices that share no network. The sending device shows it as a stream of codes; the receiving device reads them with its camera. Both sides then sign what happened.
Handshake
The receiver shows one code; the sender reads it and replies with another. From those two codes both sides derive the same session key — X25519 key agreement, HKDF, AES-256-GCM. Nothing travels over a network.
Compare
Each device shows the same six digits and five drawn symbols. The operator checks that the screens agree. This is what stops a screen or camera placed in the middle; skip it and that protection is gone.
Transfer
The file is encrypted, split into blocks and displayed as rapidly changing codes. A fountain code means a missed frame is not a failed transfer: the receiver keeps reading until it has enough blocks, and a long transfer can be paused and resumed.
Sign
The sender signs a dispatch record — content hash, work order, classification, target system. The receiver verifies the content against that hash, then signs a delivery record. Ed25519 over a fixed byte layout.
Verify
An offline verifier checks both signatures and the hash. It is Apache-2.0 licensed and needs no account, no network and no permission from us.
Evidence without the optical channel
The receipts do not depend on how the file travelled. If your file goes by approved USB, a data diode or a courier, the same command-line tool signs the dispatch and the delivery. A dispatch record is a few hundred bytes — small enough for one printed or displayed code — so the content can take one route and the evidence another.
The approval chain
A receipt says "this went from A to B". A laboratory usually needs a different sentence: "X produced this result, Y reviewed it, Z released it". Kionel can attach those approvals to the file itself, each link signed over the previous one, so the order is provable and removing a link breaks the chain.
What it runs on
A browser on each side, or a single-file command-line tool for the evidence-only workflow. No agent on the instrument PC, no driver, no network change. Keys stay in the browser's non-exportable key store.