So encrypting amateur radio comms is illegal in the US? Is there a particular reason for this?
Except that proprietary voice codices are allowed :(
Encrypting amateur radio is illegal practically world-wide — every ITU member state bans it.
With amateur radio "dying" as an interesting hobby (my opinion, but widely held) it is often speculated that if encryption was permitted in amateur radio communications, there would be quite a resurgence in interest. I predict a new generation would start to pick up the hobby and find untold uses (and abuses) for it.
Joe Taylor's work on below-the-noise signal extraction has revitalized shortwave: https://physics.princeton.edu/pulsar/k1jt/wsjtx.html , particularly at the nadir of the sunspot cycle. That's a funny sort of dying!
Amateur satellites are accessible for $100 in parts: https://www.n2yo.com/satellites/?c=18 ; with the same parts and some practice and luck you can talk to the space station. That's cool for anyone but especially cool for students; NASA will do more amateur radio work in 2018 than in any previous year. That's a funny sort of dying!
If encryption were permitted on amateur bands, I'd expect to see commercialization right quick—along the same lines as the PACTOR modems embraced by the long-duration recreational sailing community: https://www.cruisingworld.com/staying-connected-at-sea
If you are after this (why would otherwise the lack of encryption be a problem for you?) there are both better bands and cheap hw to serve such commercial traffic needs (and, in fact, regulations in many countries explicitly outlaw use of HAM bands for traffic that can be better carried by other services - including the FCC in the USA - so even if crypto was legal, it would still be illegal).
And re amateur radio "dying" - that you don't hear anyone apart from a few old geezers chit chatting on a local repeater doesn't mean it is dying. There is a lot more to HAM radio than this - e.g. stuff like amateur radio satellites, APRS, all that SDR stuff, building digital networks, experiments with radar or even good old HF contesting. Or people simply enjoy building stuff and having the ticket lets them do it legally (some countries don't allow you to own HAM radio equipment without license).
HAM radio is far from dying, just it may not be what you imagine as a HAM radio - a bearded guy in his 60s ragchewing on HF ...
(I am a HAM operator myself)
Pretending to be a ham was a form of cover.
Sadly, being a cracker-jack Morse code operstor doesn’t get you a job with the NSA any more :) Technology has moved on.
The prohibition on scrambled meaning long pre-dates WW2, and goes back to old analogies about fencing a commons.
From what I've seen out there would be a 40% improvement[1] in just base APRS if there was some form of basic FEC built into the protocol. Sadly most of "state of the art" is stuck back in the 80s.
[1] http://eludium.stensat.org/mcguire/projects/FX-25/FX-25_perf...
You need to get to UHF before doing anything reasonable (if you call 56k reasonable) and by then, your range is toast unless your friend is on top of a mountain.
Unfortunately, most folks on the VHF/UHF bands use FM radios with pre-emphasis and de-emphasis circuitry, so you would need to design a waveform that deals with those challenges.
Simple FEC just works pretty well with parity bits, just needs to be supported on all encoder/decoders.
FEC could be mistaken for encryption if the algorithm wasn't published, but the same could be said for pretty much any other digital mode. Even Morse...
Someone could resend a month old "yes" with your valid signature to a question someone asks now.
Also it might be beneficial to include sequence numbers or message IDs and for example echo the last 4 ids in following messages so recipients can detect holes. - The chat could insert some placeholder to notify recipients of missing previous messages.
This is a great idea, for both the community and as a hobby project. Has there been any other attempts at similar protocols for amateur radio?
Decreasing the complexity of the stack is a good move forward. The speeds of packet radio require a custom protocol that limits overhead but leaves options for authentication and message signing. Some hams have been using packet radio at wifi frequencies which basically creates a wireless WAN with much higher data rates, making any of the authentication methods much quicker.
I just wanted to say thank you for such a concise, clear summary. So many projects get posted with cryptic descriptions full of insider terms.
