Comment by elevation
3 days ago
FT8 has such a small payload that you couldn't fit an emoji, much less an average English sentence.
There's no authentication so anyone can pretend to be you. Traditional methods of verifying the sender (HMAC) would take so many hours to transmit that the physical propagation paths you're communicating through will probably collapse before you deliver the smallest verified message.
If you need to communicate information, FT-8 is not for you.
Agreed but if you're trapped in a war zone, time is one thing you have. And equipment for FT8 is simple to build yourself. It's also very difficult to trace. And you can take up some fields used for other stuff and convert them to data (like the sender). This would be illegal on amateur bands since it's required to identify oneself but again in a war situation this is less relevant since any covert communication will probably be forbidden anyway.
You do need a time source though. GPS is generally used for that but it doesn't need to be extremely accurate with FT-8 like with some other protocols.
I would imagine using it for a regular "I'm ok" message for the home front in such a situation using pre-arranged contents.