Read more closely: - Leveraging specific device security features would require hacking the SSL/TLS stack in unintended ways: imagine generating some form of c

Read more closely: - Leveraging specific device security features would require hacking the SSL/TLS stack in unintended ways: imagine generating some form of client certificate that used a dynamically generated set of device credentials. - Whenever possible we want to take advantage of security features provided by devices and their software. - Some devices may already contain cryptographic keys that can be used to authenticate and secure initial communication. - However service tokens can be cryptographically bound to a specific device and/or user, which prevents data from being migrated without authorization. Device keys are hardware/OS-level DRM