71–80 of 94 posts
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> So encrypting amateur radio comms is illegal in the US? Is there a particular reason for this? Encrypting amateur radio is illegal practically world-wide — every ITU member state bans it.
Notable exceptions: emergency communications in .AU and with publication of key in .CA.
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Is there a good description of what those $100 in parts for satellite work are? Or better yet, something purchasable that's likely to work? I've been wanting to get into it, but I've never found a really accessible guide to getting started in satellite communication.
Sure! To talk to a satellite you need an antenna, a receiver, a transmitter, and maybe a computer—not for voice, but for text modes. Arrow will sell you a great antenna: http://www.arrowantennas.com/arrowii/146-437.html , or you can google "tape measure yagi" and build an okay antenna. Then you can get the transmitter and receiver together, in a package like the regrettable BaoFeng UV-5R: https://www.amazon.com/BaoFe…
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Notable exceptions: emergency communications in .AU and with publication of key in .CA.
A notable exception in the US being for the telecommand of space stations (97.211b). There's also some grey area around encryption for telecommand of terrestrial craft --- you aren't allowed to "obscure the meaning of the communication" (97.215b), but other sections of Part 97 require preventing access to telecommand stations by unlicensed operators. This has raised questions over whether disallowing encryption is mo…
A replay-protected, keyed authenticator of plaintext commands (HMAC, etc) is not encryption; it is authentication. In a similar sense you are allowed to put a rolling log-in password on a packet radio BBS, so that passive monitoring will see the password, but as soon as it's revealed, it's no longer useful for additional logins.
An AX.25 packet radio chat protocol with support for digital signatures and binary compression. Like IRC over radio waves 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.
This is pretty neat, and its nice that I already have all the pre-reqs :-). Although I'm wondering if I have to use the analog cable for the radio as I've got the USB one, that will be a bit of investigation.
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There are more hams in the US, and more active hams, than ever before. That's a funny sort of dying! 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 sa…
> There are more hams in the US, and more active hams, than ever before I apologize for repeating the doom and gloom then, because I know it can be self-fulfilling. The AARL has optimism but it also tells us net licenses are up http://www.arrl.org/news/more-than-30-000-new-ham-licensees-... A decentralized, no-carrier/ISP, disaster-tolerant medium for private communication would be amazing. I am not a licensed ham so…
That can be done without encryption, though.
Take a look at Broadband-HamNet. It's exactly all these things.
Maybe messages should include a coarse timestamp to prevent replay of old messages by some adversary. 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 recipient…
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The amateur public radio bands are supposed to be open and useful to everyone so the broadcasts in those spectra are supposed to be readable by everyone as part of the accessible part. On top of that encrypted transmissions would be basically noise pumped into the system making the open uses more difficult and harder to police.
While I think this touches on a big part of it, I think the bigger thing is the need for identifying stations for accountability. If there was a protocol that emitted an encrypted blob followed by cleartext/phone callsign, it would probably be more acceptable.
§97.113 Prohibited transmissions. (a) no amateur shall transmit (4) Music using a phone emission except as specifically provided elsewhere in this section; communications intended to facilitate a criminal act; messages encoded for the purpose of obscuring their meaning, except as otherwise provided herein; obscene or indecent words or language; or false or deceptive messages, signals or identification.
(§97.207 outlines the space station exception)
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> There are more hams in the US, and more active hams, than ever before I apologize for repeating the doom and gloom then, because I know it can be self-fulfilling. The AARL has optimism but it also tells us net licenses are up http://www.arrl.org/news/more-than-30-000-new-ham-licensees-... A decentralized, no-carrier/ISP, disaster-tolerant medium for private communication would be amazing. I am not a licensed ham so…
If you want that, there are plenty of ISM bands and loads of cheap equipment you can use to build such "decentralized, no-carrier/ISP, disaster-tolerant medium for private communication" (aka internet ...) HAM radio bands are meant for R&D work, learning and basically hobby stuff, not to replace internet or phone services - in fact, the regulations explicitly forbid such use.