A Hardware Privacy Monitor for iPhones
Andrew “bunnie” Huang and Edward Snowden have designed a hardware device that attaches to an iPhone and monitors it for malicious surveillance activities, even in instances where the phone’s operating system has been compromised. They call it an Introspection Engine, and their use model is a journalist who is concerned about government surveillance:
Our introspection engine is designed with the following goals in mind:
- Completely open source and user-inspectable (“You don’t have to trust us”)
- Introspection operations are performed by an execution domain completely separated from the phone”s CPU (“don’t rely on those with impaired judgment to fairly judge their state”)
- Proper operation of introspection system can be field-verified (guard against “evil maid” attacks and hardware failures)
- Difficult to trigger a false positive (users ignore or disable security alerts when there are too many positives)
- Difficult to induce a false negative, even with signed firmware updates (“don’t trust the system vendor”—state-level adversaries with full cooperation of system vendors should not be able to craft signed firmware updates that spoof or bypass the introspection engine)
- As much as possible, the introspection system should be passive and difficult to detect by the phone’s operating system (prevent black-listing/targeting of users based on introspection engine signatures)
- Simple, intuitive user interface requiring no specialized knowledge to interpret or operate (avoid user error leading to false negatives; “journalists shouldn’t have to be cryptographers to be safe”)
- Final solution should be usable on a daily basis, with minimal impact on workflow (avoid forcing field reporters into the choice between their personal security and being an effective journalist)
This looks like fantastic work, and they have a working prototype.
Of course, this does nothing to stop all the legitimate surveillance that happens over a cell phone: location tracking, records of who you talk to, and so on.