Comment by dragontamer | Hacker News Reader

Comment by dragontamer | Hacker News Reader

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> The premise is these folks have never met, and assuming that the cronies aren't familiar with the tech and told to "go to this bench, do this workflow, enter in these codes". Rather they were told to download an app to their phone, go to this area and "start chatting", or maybe they connected to the bush server, and exchanged messages without ever having to be in the same place at the same time.

I'm pretty sure walkie-talkies can be purchased at any street-corner and replicate this.

Even toy walkie-talkies in the USA follow the FRS standard and have roughly ~1 mile or so of range (3 to 5 miles for more expensive walkie-talkies). Meaning you can have an untrackable "virtual meetup" with strangers as long as you all coordinate a time, place, and channel to talk.

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If you want more smarts, you'll want to:

1. Use LoRa -- 900MHz (800ish in Europe) is superior for range. Bluetooth is 2.4GHz and attenuates too quickly, and is therefore short-range only (a few hundred meters reliably).

2. LoRa modules are cheap. Arduinos, ESP32, Beaglebone ConnectPlay, etc. etc. A ton of different microcontrollers and microprocessors exist. Slap a solar panel + lead-acid battery on a BeagleBone Play or something and now you got 24-hour always on servers with 3 to 5 miles of communication range. Add on TLS1.3 and now its encrypted to the latest and greatest specifications of encryption available.

Walkie-talkies are still unconventional technical items. Everyone has a phone - homeless people have phones. Phones are ubiquitous, and someone having one is not unusual.

They might be lower-tech, but it is odd if someone has a walkie-talkie - also easy to monitor (range == eavesdroppers have range too) and it is in fact illegal to use encryption over the available frequencies or to send digital data (so all things you could do, but which would draw attention).

The problem with committing crimes is that efforts to cover up the crime themselves are likely to create evidence of it.

> and it is in fact illegal to use encryption over the available frequencies or to send digital data

Send it in encrypted Morse code.

Probably illegal but Morse code is itself legal and who out there would even know if some doo-dah-dahs were in fact encrypted anyway?

But LoRa is the more legitimate long-range module for home made digital comms (encrypted) in any case. And should be easier to do.

> which would draw attention

Unless you're disrupting military / police / aviation frequencies, there is virtually no enforcement. The FCC does not routinely police the airwaves - they can be asked to investigate egregious disturbances, but if they do choose to respond (which is rare), that response will not start for weeks or months. Nobody is going to show up with guns drawn for an encrypted LoRa connection.

LoRA is very neat, been playing with Meshtastic lately a bit - only downside is how fucking chatty it is, which makes it very easy to perform direction finding / trilateration using something like a KrakenSDR (or just a normal SDR and a directional antenna).

At some point I’d like to mess with trying to do “burst” comms over LoRA, maybe meshtastic can be fiddled with to act in this manner - where it only actually sends RF traffic when it has something to say.

I just double-checked and I got my initial spelling (LoRA) wrong. Its actually spelled (LoRa) (lower-case a, not an upper-case). I've edited my earlier message to correct my mistake.

LoRA is the LLM / deep learning stuff. LoRa is the radio. Hurrah, overloaded terms!

You can configure the spreading factor and bandwidth to make the bursts very short, at the cost of robustness to interference etc. And transmit at sparse intervals if you want.

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