by Alec Muffett
…otherwise we would be hearing about this story for months. Nonetheless, we are probably still going to have people in government screaming about “banning software defined radios” because they think that is how cybersecurity works:
US railroad industry’s outdate radio protocol is vulnerable | The Register
@alecm BBC ran a report the other day trying to get "Deauther" watches dropped from Amazon, because of security issues with Ring doorbells.
The thing people forget is that an SDR is not a complicated piece of hardware to build, assuming you don’t care about out-of-band emissions and other such things that regulators care deeply about.
BOM is on the order of £1,500 for a low power 25 MHz wide SDR transceiver running at DC to 5 GHz, design and construction is something a motivated radio amateur can do, with something along the lines of an Intel Celeron as the compute.
Another £1,000 or so BOM gets your amateur a 100 W output linear amplifier in a band of interest.
Add another £500 of copper pipe and cable ties, and you can build a directional aerial for the band of interest with ease.
That’s £3,000 for a motivated attacker, working from parts, and building something they can use from a long way away. They’d have to learn RF design theory, but there’s a lot of published resources there.
Oh, and since they’ve probably made mistakes that lead to out-of-band emissions, they’ll also disrupt things like mobile networks while playing. At least the commercial SDRs only disrupt the frequencies you’re transmitting on.
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