273 points | by joebig4 days ago
The talk is about her attempts to learn about the Radio RDS (Radio Data System) standard, using a sound card to decode signals, finding a bit of bus-related information in that stream is weakly encrypted and proceeding to chasing it down. Very entertaining.
I'm so glad such people exist. I wish I could be one of these fearless and supremely knowledgeable people!
There's no trick to it (or there's a massive trick to it), you just refuse to let a mystery go until you know what's happening, mostly because figuring things out is fun.
In the process, you gain a large amount of knowledge.
I also think that figuring things out is one of life's most rewarding experiences.
But I've found out a lot of people don't think like that. I've often been asked "but why are you doing this" on the topic of my "eccentric" projects. People often can't understand why I find it fascinating because they would only find it tormenting.
Of course I did a search in the Play Store but it's crowded with streaming radio apps and SDR apps.
https://www.gsmarena.com/results.php3?chkFMradio=selected returns 7010 models, lol.
edit: oops you mean specifically RDS. Of that I'm not sure. I just opened the "Radio" app on my phone (for the first time ever!) and you did have to have the headphones plugged in to receive, but I couldn't see anywhere in the really basic looking app for RDS info to show up.
Besides that, FM broadcasting isn't a lawless place and is regulated by the government. Abuse will most likely lead to some kind of penalty, but I can't be bothered to read through the laws to confirm it :P
Have a link or info on this? Sounds interesting but can't find anything.
Back in the day, it wasn't uncommon for pirate radio stations to drum up listeners by using TA to advertise short snippets.
I love that hacker mindset :)
Another more advanced technique is Code Division Multiple Access (CDMA), e.g. used by GPS and some mobile communication modulation schemes. It allows you to have multiple senders on a single radio carrier frequency, and the receiver "selects" which sender to listen to by knowing its "code".
There's also Time Division Multiple Access (TDMA), i.e. senders take turns sending content in allocated time slots.
https://www.mediarealm.com.au/articles/fm-rds-radio-data-sys...
- Sad to request, but can you take thisoffline. It is kind of our service you hacked :)
[1]https://www.windytan.com/2013/05/a-determined-hacker-decrypt...
Unless something is theoretical impossible, the only thing stopping a determined hacker is the amount of time and coffee in reserves.
I don't think the fact that it worked in generating clicks is really an argument for bait titles. Given the positive comments about the content I think some editorializing could have been helpful to focus on the hacking journey aspect though, which seems to be the point rather the specifics of RDS itself.
Alternate data streams in FM like RDS, IBOC audio and FM time are not some new-fangled tech. This would/should be the first place to go to if you saw a signal that’s not modulated to analog audio.
Of course, the whole mystery aspect is just a hook and helps move the story along.
This was just ('just' for her, impressive for me) an exercise of going down the rabbit hole, and then curating that tour for us.
> I was looking at FM radio channels on SDR (rtlsdr came out in 2010) and noticed the RDS. So I looked into it.
I’m not a fan of a fabricated premise in order to show “look how brilliant I am, I discovered RDS from first principles” when this mostly documented (1).
In contrast, look at the Mike Harrison Eidophor talk. The guy pieced together a history of a significant technology that is otherwise poorly recorded on the Internet (2). This is new and novel info.
(1) https://www.2wcom.com/fileadmin/redaktion/dokumente/Company/...
(2) https://hackaday.com/2016/04/19/mike-harrison-exposes-hot-oi...
I think the more fun part was towards the end, when she brute-forced decryption keys for traffic information coordinates and also found the (AFAIK) non-standard Finnish bus stop time table information in another band and reverse-engineered that, and I think that was the takeaway of the talk.
Secondly, while individually each thing is independently documented (RDS, Nyquist criteria, sound cards, FSK/QPSK, etc), it is nice to see someone bring all of it together. Surely you don't mean to say that you have not relied on web resources to pull together a project, where one _could_ go to more primary sources, but you are thankful that someone showed you the way?
Like someone said, "Look around you. Everything is someone's passion project". I welcome everyone's passion project. It is not noise if I am interested.
Obligatory XKCD “Ten Thousand” https://xkcd.com/1053/