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Comment by gruez

1 day ago

>ADB / forensic tools would be ineffective if USB access is denied (as discussed elsewhere in this thread).

Well no, because if you gave the pin, you'd expect the phone to work normally, including enabling adb. If you gave the pin but adb doesn't work that would be massively suspicious. Same if adb worked but logs were scrubbed. Otherwise you're back at "border guards found out you gave a duress pin, now you're being prosecuted for tampering with evidence".

It doesn't feel like you're very interested in solving this problem - you seem more interested in defending the status quo

  • In fairness, an adversarial challenge can be useful in pointing out weaknesses (and possible mitigations) to a particular technical approach.

    It's not clear that all of those objections are substantive or insurmountable.

    "The USB port may have died" might be one possible response. (Not technically a lie, and hence defensible in court.) Or just silence.

    Alternatively, some way of directing such probes to the decoy partition and presenting a sufficiently coherent impression of a valid partition might be another approach.

    Much of this comes down to risks presented and costs of mitigation (or of getting mitigations wrong).

    • >"The USB port may have died" might be one possible response. (Not technically a lie, and hence defensible in court.) Or just silence.

      That's about as convincing as "wow this phone just decided to experience catastrophic hardware failure after entering your totally-not-duress pin". Not to mention there's wireless adb.

      >Alternatively, some way of directing such probes to the decoy partition and presenting a sufficiently coherent impression of a valid partition might be another approach.

      That won't work because they'd notice the adb logs don't correspond to actions taken on the actual phone.

      >Much of this comes down to risks presented and costs of mitigation (or of getting mitigations wrong).

      Right, which is why grapheneos didn't bother implementing it, because it's a huge effort and it's not worth giving users a false sense of security (eg. thinking that the decoy works when it doesn't), and them getting sent to prison for it.