I’m talking about this article that I remember reading last year, but I never fully comprehend it. https://archive.md/qgBWB

Especially one of the images:

What does “BFU Extractions” mean? Does it just straight up bypass any lockscreen, even Before First Unlock?

The first time I came across that article, I just assumed if you have a strong password, your fine, now I’m not so sure, I’m starting to get a bit paranoid… 😖

    • bamboo@lemmy.blahaj.zoneEnglish
      12·
      2 days ago

      It’s possible that they discovered a weakness in the way the keys are generated in the TPM (or whatever it’s called for Android), which brings the time to brute force down from 1,000 years to a few weeks with massive GPUs?

      Similar story, as of a few years ago, OpenSSH announced deprecating support for RSA keys keys because of a vulnerability in SHA-1 hashing, where they cited research showing a determined attacker could break the key with $50k of compute power, which may seem like a lot, but is pretty feasible, necessitating the deprecation

      It is now possible [1] to perform chosen-prefix attacks against the SHA-1 hash algorithm for less than USD $50K. For this reason, we will be disabling the “ssh-rsa” public key signature algorithm that depends on SHA-1 by default in a near-future release.

      I don’t know about the Android system, but during the initial design and fabrication, the hardware may have not been designed to withstand the compute power just a few years later, and can not be easily updated to improve the security. These are the weaknessed Cellebrite is looking for.

      • catloaf@lemm.eeEnglish
        9·
        1 day ago

        $50k of compute power, which may seem like a lot

        To an individual. For a business, that’s a quarterly spend. For the government, it doesn’t even come up in budget reviews.

    • buffing_lecturer@leminal.space
      14·
      2 days ago

      Theyre not saying anything about reading the key off the phone. Brute force the key by trying every key against the encrypted data dump.

    • Max-P@lemmy.max-p.me
      4·
      1 day ago

      It’s derived by both a key from the TEE and the PIN/password.

      The reason for that is so you need both the user’s correct password, and the TEE to agree to hand out the key, which it may refuse to do if there’s been too many attempts. When you factory reset it just generates a new key, instantly making all the previous data permanently inaccessible. The TEE will also wipe the key if you unlock the bootloader or try to break in the wrong way.

      It’s still only roadblocks though, extract the key from the TEE and you have unlimited attempts on what are usually weak 4-6 digit PINs. It’s not a lot of tries. Then you better hope you had a good password.