shellhamer There's important data left on the phone—is there any other way to recover it?
Some parts of the Pixel security architecture stand in the way:
- Each profile's storage encryption key is a mixture of the PIN/passphrase entered by the user and a "second half" of the key that is held by the Titan M2 secure element. The secure element won't mix in its half of the key until it receives the PIN/passphrase and the kernel running on the device is signed by the same signer as the kernel that was running on the device when the PIN/passphrase was set.
- The secure element won't release the storage encryption key to the kernel ever. Instead it provides the kernel with a locked box containing the storage key, that can be unlocked only by the flash controller.
Thus, without heroic measures such as disassembling the device and using forensic tools, or the deployment of a hypothetical unpublicized grievous security vulnerability, the only way for anybody to get access to the data is for a GrapheneOS kernel to boot and then for enough GrapheneOS user-space programs to work that the lock screen shows up and the PIN/passphrase is entered and conveyed to the secure element. The system is carefully designed so that nothing else will enable access to the data.