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I'm using an STSAFE chip - the same IC they use in StarLink terminals. Essentially the digital equivalent of a holographic barcode. I have some other protection
by chipweinberger 3mo ago
I'm using an STSAFE chip - the same IC they use in StarLink terminals. Essentially the digital equivalent of a holographic barcode. I have some other protections too. e.g. Random 128-bit per-device IDs / product-keys. iMessage uses this strategy.
Maybe I'll write an article about that.
- stavros 3mo agoPlease do, that'd be very interesting. I imagine it's doable to use random per-device I'd when you're hand-flashing, but probably harder on a huge production run.
- swiftcoder 3mo agoAlmost all commercial devices need a unique ID, private key, etc burned in on the production line. For a big enough production run, you'd likely ship an HSM to the factory
- chipweinberger 3mo agoIMO it's better to ship preprogrammed ICs to the factory, so you can do your secure burning in-house.
- swiftcoder 3mo agoDepends on where the ICs originally come from. No point shipping your ICs from China -> US, flashing them, shipping them back US -> China for assembly, and then ship them China -> US again to sell
- Teknomadix 3mo agoYet people do this all the time. Ask me how I know.
- thenthenthen 3mo agoCan reply to the reply below but yeah, i have done that, lol
- Hackbraten 3mo ago> For a big enough production run, you'd likely ship an HSM to the factory I figure that the factory is exactly the adversary in the whole threat model? So why give them the keys to the castle so they can moonlight their own genuine batch?
- NBJack 3mo agoA few ways, if I understand them correctly. On-site people you employ (if you can afford it) auditing the process, connectivity to the HSM to record every key assigned (makes it easy to trace duplicated keys to their origin), and ideally assigning these keys at the very last possible step after the rest is assembled (to minimize 'defective' parts wandering off and being assembled elsewhere).
- swiftcoder 3mo agoYeah, it's important that your own people are doing regular inspections of the production line, keys get burned at the final station (use temp keys for QA stages before that point), and you retain software control of the HSM. You probably aren't going to do this whole rigmarole for small runs of devices like in the OP.
- chrismorgan 3mo ago> Almost all commercial devices need a unique ID, private key, etc Serious question: why?
- swiftcoder 3mo agoYou want a unique ID so that you can track which units are experiencing issues, you want private keys to be able to securely connect to your backend service and/or mobile companion app. A local-only device with no telemetry can probably skip some of those
- rustyhancock 3mo agoSounds like that'll be a great read. This is (literally) none of my business, but would you consider a cut down or basic open source version (hardware and software, with open software running in the proper hardware). Yes it'll be cloned by factories, and yes it will cut into sales no matter what proponents claim. (And yes it's probably more work than I imagine it is). But also yes, it'll be genuine open hardware and might out live your interest in the project.
- c0nsumer 3mo agoReading your comment it sounds like you're asking the author to do more work to potentially/likely undercut their own sales. They are already offering a quality device at a reasonable price without any untoward restrictions. If you want a Free work-alike, why don't /you/ put in the work and make it happen?
- _fw 3mo agoPlease do! Trying to imagine how this works.
- DANmode 3mo agoPlease!
- amelius 3mo agoHow do you verify the ID? In the software? What if the software is hacked? I'm curious how this can be safe.
- Teknomadix 3mo agoYes, please do!