5 ms·

Exactly my first thoughts. Key is derived from "user-controlled data". That makes sense, it's my phone, isn't it? Why would the phone need to encrypt data in a

• ZiiS 5y ago
  The user positive use is securely booting to a password prompt to decrypt your data. Without this security working, anyone who steals your phone will be able to get all the data you have saved on it.
  • d-gearloose 5y ago
    That's kind of the thing with Microsoft's bitlocker as well. It automatically decrypts the hard drive on boot, so the only thing it could protect you from is someone removing the hard drive and mounting it somewhere else. But if they have physical access to the device, why would they do that?
    • dwattttt 5y ago
      That's the default configuration for bitlocker, but there are others, including requiring a password or key provided by USB on startup
    • vladvasiliu 5y ago
      I think the idea is that Windows' security, once booted, is enough to protect your data. It's the same situation if, for example, your laptop gets stolen while in sleep / on the lock screen. In theory, you shouldn't be able to get the key while booting on some other media (say, your own Windows USB drive). > Ensuring the integrity of early boot components and boot configuration data. On devices that have a TPM version 1.2 or higher, BitLocker uses the enhanced security capabilities of the TPM to make data accessible only if the computer’s BIOS firmware code and configuration, original boot sequence, boot components, and BCD configuration all appear unaltered and the encrypted disk is located in the original computer. On systems that leverage TPM PCR[7], BCD setting changes deemed safe are permitted to improve usability. https://docs.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-countermeasures https://docs.microsoft.com/en-us/windows/security/informatio...
    • sissjdb 5y ago
      Physical access does not imply easy arbitrary code execution. Consoles are largely protected by the same technology, how often do you see people achieving code execution on them by tampering with the hardware?
      • roblabla 5y ago
        All the time? Hardmods have been a thing since the first consoles, all the way down to the latest Nintendo Switch. Also, consoles are "protecting" not the user, but the manufacturer - which is exactly the point people are trying to make.
        • sissjdb 5y ago
          Haha. You’re bringing up tech from 20 years ago when we’re discussing modern security measures, aren’t you very clever. What hardmods do you know of for current gen consoles? Even the previous generation mostly fixed all public hardware based attacks. This is standardized hardware that would be a relatively soft target to build tooling against, yet modchips are essentially dead because the attacks are just far too difficult.
          • llbbdd 5y ago
            This is pretty confusing, hardmods are definitely a thing for the current gen Switch - AFAIK it's the only way to jailbreak ones that were manufactured after some date and don't allow soft mods.
            • sissjdb 5y ago
              Nintendo famously has the worst security of all the console manufacturers. That there are still no good attacks for the xbox one speaks volumes.
      • nest0r 5y ago
• olliej 5y ago
  No, what you want is a random key. The security properties of an n-bit key depend entirely on those n-bits being random. Derived from user data is not (A CSRNG is not secure if the initial state is predictable). The way security on modern devices with h/w support work is that a random key is generated in hardware. Subkeys are derived from that. Access to these keys (if they're ever directly exposed) is gated on the correct password, but nothing is actually protected by it. This is what you want as it means you don't have to make a password that is maybe 50 characters long, and actually random (e.g. no word sets).