Challenged. Signed. Verified.
Identity for the lower airspace.
Ground stations challenge every node in range. Each one answers with a signature that cannot be forged, from a key that never leaves the chip. The identity holds while the airframe, the operator and the mission change underneath it.
30 m mast · permanent coverage · thousands of nodes per station
Upper airspace solved identification with ADS-B. Below 120 metres there is no equivalent. Remote ID identifies an airframe and announces an identifier that anyone can copy: built for accountability, not for assurance, and broken the moment a fleet operator swaps an airframe or leases a fleet out.
UAID, Unified Airspace Identification, identifies the hardware node, proves it cryptographically on every response, and keeps the identity constant while ownership, operator and airframe change underneath it in a time-stamped registry. It answers the question neither ADS-B nor Remote ID can: is this aircraft really the one it claims to be, and who was legally responsible for it at 14:22 UTC?
THE GROUND STATION IS THE OBSERVER · It challenges, measures the response itself and verifies it against the registry. Nothing reaches UTM on the strength of what an aircraft claims about itself, and an unsigned or geometrically implausible response is dropped before it ever gets there.
The identity key is generated inside a secure element at manufacture and can never be read out. Copying the identifier gets an attacker nothing, because without the key there is no valid signature.
Each answer carries an elliptic-curve signature over a single-use challenge. The station verifies it in milliseconds and drops anything it cannot verify, before the track reaches UTM or ATC.
Identification never depends on what the aircraft says about its own position. GNSS jamming and spoofing, now routine across eastern Europe, degrade the picture; they do not blind it.
The technology is the same in both cases. What differs is what has to be true before it can be used. Military and state operations sit outside the civil framework by law, so nothing has to be agreed first. Civil U-space deployment needs an authority at the table, and that is where the mandate, and the volume, will come from.
Now · State and defence
A station challenges, a node proves itself with a key that cannot be copied. That is the IFF principle, applied below the altitude where Mark XIIA Mode 5 lives, on platforms that cannot carry a Mode 5 transponder for reasons of mass, cost and export control.
Next · Civil U-space
U-space makes identification a service obligation rather than a good idea. UAID is built to supply it at an assurance level above an unauthenticated identifier, and to carry the ownership record that a broadcast cannot.
The node and the protocol are identical in both. What changes is the station: a permanent installation that covers a corridor or a city cell, or a case-sized unit with a telescopic antenna that an operator carries to the mission and switches on.
Fixed site
Permanent coverage for a vertiport, a corridor or an urban cell, published into UTM and ATC and logged without interruption.
Mobile kit
A case-sized station with a telescopic antenna for mobile missions, exercises, temporary sites and incident response. Set it down, extend the antenna, and the picture is there.
04 · Two ways in
We are selecting pilot partners for the 2026 city deployment, and manufacturers who build the node into the airframe while the mechanical and electrical interface is still open. Both start with a technical session of thirty to forty-five minutes.