• 10 Posts
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Joined 1 year ago
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Cake day: June 7th, 2024

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  • The minute the Pi4 compute module showed up, the jig was up.

    For the secure boot scheme to be really secure, you have to generate a unique key for each device. Most vendors don’t bother because it means each firmware update has to be signed and encrypted for each unique device. This also means you have to have the infrastructure for device attestation. You can’t just stick an update file on a public S3 bucket or FTP site like the good old days.

    Some end up reusing the same product key, so if it’s compromised, all devices in that family can be hacked. But even that’s too much for some vendors.

    Instead, they just wing it, and go back to the bad old habits (no encryption, or symmetric keys embedded in firmware) that get them featured in DefCon presentations.




  • The problem with these trackers is that the Bluetooth scanner needs to run in the background on the phone, which means you have to give the app a lot of privileges and the constant scanning can drain the phone battery more quickly.

    Google designed a nice Tile/AirTag beaconing alternative called Eddystone that ran as a system service and was pretty well-optimized. Unfortunately, they shut the whole thing down, so it’s every app on their own.

    There are programmable ones out there. I’ve had good luck with a developer-oriented brand called Blue Charm Beacons. There’s a small version with a button, but don’t think it’s rechargable. Or search for “Tile” on AliExpress.