It's the password required to decrypt the secret key that you would not need to disclose. They'll likely end up with the encrypted secret key, but no way to access it. That's because the password is something you know, and divulging it could mean self-incrimination.

Courts have ruled, for example, that the police can compel a suspect to put their face or finger up to a phone to unlock it through biometric means, but a suspect cannot be compelled to divulge their PIN. That's why using biometrics, while convenient, is a bad idea.