Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption
Full disk encryption (FDE) is a UX issue, not a technical one. You don't need a secure cryptographic processor, but the UX sucks without one.<p>A simple, working, FDE setup would be something like LUKS running at boot:<p><pre><code>    1. Turn on phone
    2. Phone loads up initial bootstrap OS
    3. Phone prompts user for master key
    4. Master key is used to unlock volume
    5. Regular OS boot continues
</code></pre>
If the master key has enough entropy, brute forcing it becomes impossible. The phone won't "disable" as there's no self-destructing component (i.e. "secure crypto chip") but that doesn't mean it can be cracked. Boil as many oceans as you'd like, you're not going to brute force 256 bits of entropy.<p>The UX problem is that the master key is a PITA to enter if it's long enough to be cryptographically secure. That's what a crypto chip is supposed to solve. A limited number of attempts with a shorter passphrase.