For most of the history of military communications security, the question that mattered was whether the enemy could read your traffic. Ciphers got stronger, keys got longer, and the people who designed radios measured success by whether an intercept could be decrypted.
The war in Ukraine has made that framing look incomplete. Public assessments of electronic warfare there, including those from RUSI, describe a battlefield where the most dangerous thing about a transmission was not what it said but where it came from. Direction-finding integrated with fires turned emissions into targeting cues. A radio that is perfectly encrypted and perfectly locatable is, in practice, a beacon that can kill its operator.
Three exposures a cipher does not touch
It helps to separate what an adversary can learn from a net into things encryption protects and things it does not.
Content is what a cipher protects, and modern ciphers protect it well. The adversary's problem is rarely there.
Emission is the fact that a transmitter is radiating, from somewhere, now. Encryption has nothing to say about it. Every transmission is an opportunity for direction-finding, and the command post, which talks most, is the loudest node on the net.
Metadata is the shape of traffic: volume, timing and who talks to whom. Brigade traffic rises before an operation, every time. Order of battle has been derived from traffic analysis since the First World War, and EMCON exists as a doctrine precisely because a better cipher does not help.
There is a fourth exposure that is not about the air at all. When units cannot distribute keys fast enough, they fall back to whatever works, including civilian handsets. That is a key-logistics failure, not a cryptographic one, and it is just as fatal.
A stronger cipher fixes none of emission, metadata or key logistics. They are structural.
What changes in the design
If the threats that matter are structural, the response has to be structural too. That is the premise behind everything we build: rather than hardening the thing an adversary attacks, remove it.
- Remove the key from the device. If no long-term key exists on a radio at rest, capturing one yields nothing to exploit, and losing one stops being a net-wide re-key. Units stop having a reason to delay reporting a loss.
- Remove the single link. If every message is spread across every bearer a unit carries, jamming one band degrades delivery gracefully instead of forcing silence.
- Remove the traffic pattern. If every node emits at a constant rate, volume stops revealing tempo, and the busiest node stops standing out.
The honest part: emission still has a cost
It would be convenient to claim that these measures also defeat direction-finding. They do not. A radio that transmits at a constant rate is, if anything, easier to find, because it is always transmitting. Constant-rate emission defeats traffic analysis; it does not hide the emitter, and transmitter fingerprinting can still distinguish one radio from another.
Emission therefore has to be managed as a budget: transmit less when the EW picture is hot, push traffic onto bearers that are harder to locate, and make the exposure visible to the signals officer. Some of the answer will always live in the radio and the waveform rather than in software. We would rather say so plainly than let a metadata claim be read as a DF claim.
What this means for evaluation
If you are evaluating secure communications for a contested environment, the questions worth asking are not only about the cipher:
- What does an adversary hold after capturing one radio intact, powered on, with the passphrase?
- What happens to delivery when the primary band is jammed?
- What does the traffic timeline look like to an observer in the days before an operation?
- How many hours does the emission discipline cost on a dismounted battery?
Those are the questions our reference lab lets you test in a browser, and the ones we want answered in a user trial with a real signals regiment.