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by manjushri 2995 days ago
>Literally anyone with software to generate NOAA SAME tones, together with a software-defined radio and amplifier, can walk near one of a handful of "primary entry points" and belt out an alert that gets mindlessly repeated across the country.

So a fake alert can be sent out nationwide from broadcasting to just one access point??
4 comments
finnthehuman 2995 days ago
No. EAS doesn't cascade like that. Broadcasters are only mandated to monitor 2 stations, and the monitored stations are upstream in a distribution hierarchy. I can't speak to every broadcaster's configuration, but it'd probably propagate 2 or 3 hops.
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ashleyn 2995 days ago
I don't really know the precise technical details, but owing to how these stations serve as entry points for other stations, I would surmise all one would have to do is impersonate the original station and hundreds of other broadcasters would immediately begin relaying an alert in a mesh configuration. There is no authentication on this process (or at least there wasn't in the initial days of EAS before CAP/IPAWS), and any rogue ham or Russian spy could do it.
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X-Istence 2995 days ago
Yes.
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mschuster91 2995 days ago
> So a fake alert can be sent out nationwide from broadcasting to just one access point??

I believe OP meant "country" as in "countryside", which is feasible when you're up on a hill and your signal can reach a distribution source antenna (which will then distribute your spoofed alert to its attached sirens).

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ashleyn 2995 days ago
No, I meant the country as in the United States. EAS on the national level works by playing telephone: hopping the alert from station to station in a mesh configuration. PEP stations are origins for national alerts.
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mschuster91 2995 days ago
Oh wow. Clearly, something like widespread availability of SDRs was not an issue back then.

I wonder why it hasn't been abused/trolled on a large scale, though. Really, if I were interested in trolling that's what I'd do: next to zero chance of the cops catching you as you won't leave a trail, plus the entire country will be wide awake once the sirens ring and it will likely need months or years until the government secures the stuff.

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