Securing a travel iPhone
blog.filippo.io
blog.filippo.io
To frame the post and the conversation, I am targeting a loose but not universal threat model. If threat of deadly force is higher up in your risk scale than shoulder-surfing, or Apple cooperation is a given, then you might want to make very different choices, but more importantly, you probably need better advice than a blog post.
The only things I want to add are pair-locking, maybe a forced VPN profile, and a correction on how to check the Whatsapp fingerprint. You can find all these things in the Twitter thread.
Once the phone is unlocked, you can use TouchID as the phone is already open and you would not gain/lose anything from using TouchID in that scenario. But until the courts rule that you cannot be compelled to TouchID unlock your phone like a PIN, I think that is the safer route to take for now.
It's all about the threat model.
Keychain and NSFileManager have possible modes of "kSecAttrAccessibleAfterFirstUnlock" [0] and "NSFileProtectionCompleteUntilFirstUserAuthentication" [1] respectively that are (fittingly) in an open state within your app after you've unlocked the device.
[0]: https://developer.apple.com/reference/security/ksecattracces...
[1]: https://developer.apple.com/reference/foundation/nsfilemanag...
As an aside, I've found that, at least with my iPhone 5S, if my finger is wet (e.g. if I've licked it), it also is rejected.
That's why this https://support.apple.com/en-us/KM205083?cid=acs::applesearc... article states to contact them.
What is even the point of Find my Phone and all that if anyone can just instantly switch off all the tracking?? You can't even ring your own number after that, and even law enforcement cannot look up the cell tower logs to see where it's been.
There should be an option to require a passcode for power-off, and another option to periodically send Find my Phone tracking even when "powered off," via any available network, until the battery dies.
EDIT: I agree they can just take out the SIM and we need to be able to force-power-off anyway.. but what can be done to increase the recoverability of these expensive items?
sleep/wake+home button restarts iOS but ultimately reconnects to the device to the web.
You have to think about it from the attacker's point of view. Anyone they sell it to is going to power it on to test it. Once it's powered on, it'll ping back.
Any black-market buyer knows to pop the SIM anyway before powering it on, and turn on the phone without any publicly-accessible Wifi access points available. But then they still have to restore it in order to see if it's iCloud locked, and the restore pings, too (it requires an Internet connection to Apple's servers to download a signed OS.)
What it comes down to is that stolen iPhones just aren't worth that much, since there's no easy way to remove an iCloud lock and the parts themselves aren't worth a lot. The good news is that far fewer iPhones are stolen these days (source: http://www.cbsnews.com/news/iphone-thefts-down-thanks-to-app... ), and thieves are pretty quickly learning that.
New screens are pretty cheap these days; under $40 for a new iPhone 6 screen wholesale currently. Used batteries are worth nothing since new batteries are so cheap (a new 6 battery is less than $10 -- why would you want a used one?) Camera, home button, charge port, prox sensor...even if you put all those together you'd barely have $100 worth of parts, and that's talking about new part prices (wholesale).
You go to https://www.icloud.com/activationlock/
The only place where you would not want to use biometrics are western* countries which would allow the police to compel you to give out your fingerprints to unlock the phone.
With the exception of the UK in which not giving out a password or decryption key in the course of an investigation even if you are not the suspect of a crime can land you 7 years in prison these days.
I'm not so sure about that...
I worked at a TV news station in a major city where police told us they could track cell phones that were turned off. IIRC, it came up during an interview after they apprehended a suspect in a big rape/murder case. The suspect's phone was off, but they were able to track him. They told us they didn't really want the public to know they could do this, but it seems it's too late for that [1].
I'm not sure what the limitations are-- whether it'll work if the battery is removed (maybe there's amother battery?) or whether it only works with certain phones.
[1] https://www.quora.com/Can-law-enforcement-track-someone-by-t...
The NSA* or any other similar actor can load malware to your phone that would prevent it from being completely turned off, the police most likely cannot.
The police does have a vested interest in making the public think that turning the phone off is pointless.
*on older phones like late 90's very early 2000's there was enough power leaking from from the antenna into the modem part that you could ping turned off phones remotely even if the battery was removed I've seen this in action. This doesn't or shouldn't work on new phones which require considerably more power and have very complicated hardware.
I don't see how that could work - even if power through the antenna did cause the phone to transmit something, more than the radio would have to be powered up to get the phone to return any kind of identifier. But I'm skeptical that any transmitter could be powered through the antenna like that.
I could believe that if you transmit enough power that some sort of oscillation would occur in the phone to return a signal that can be detected, but I don't see how you could determine what phone returned that signal.
I would assume that you would profile phones (of a certain make and model) and based on the return signal identify them. This was used in the early days of in places where there wasn't high cellphone density to begin with.
Only device that I'm aware that's able to do this is designed for this application.
Those aftermarket lighty-uppy things work by sensing your phone's response burst, which is a much stronger signal, being driven by the phone's battery, and radiated from the very nearby antenna.
I do believe that you can induce a signal in a powered-off phone that can be detected nearby (several feet), by virtue of the tuned antenna if nothing else. I'm skeptical of the claim that a normal arbitrarily-distant cell transmission could do so. Regardless, I do not believe the induced signal could be detected back at the cell tower.
This would be wireless power. Not possible, at the levels and ranges asserted.
I've seen this demonstrated around 5 years ago at an Intelligence Technology seminar open to the public at the intelligence community heritage museum, it was done across the room during a demonstration which showed active and passive phone tracking techniques (they put the phones in and out of a faraday cages during the demonstration). The phone that was used in the demonstration for the "powerless" tracking was a very old Ericsson (before it became Sony Ericsson) phone from the mid to late 90's, during that demonstration we've also been told that this method of tracking became obsolete around the early 2000's. They did not elaborate exactly what ranges this work on but what they said is that the emitter and receiver were usually separated in order to accommodate operational requirements.
Am I misreading your statements?
You're forgetting about the baseband. Modern phones have a secondary processor loaded with proprietary software that has a secondary battery soldered on. You can't turn that device off, and it has the ability to phone home. Even removing the battery won't help you.
An interesting point, but...
If I were a criminal (I am not), and I were going to commit a crime (I am not), and I knew turning off my phone was pointless because the police can still track it, then I would just leave my phone at home, or give it to a friend.
As far as I know phones today don't do this.
Move to a place with thieves who know not to steal a really hard to move phone.
Don't buy or walk with expensive items around? Sounds like I am being snarky, but I am serious. In some cities or areas, it is not possible to have nice stuff around. Couldn't have a nice car in my old neighborhood. The old beater I had was scratched, hit and broken into multiple times. I didn't care too much, as it was already scratched and beat up anyway. If it was a nice new car, I would have been upset, but I would have never gotten a nicer car living in that part of town.
As for phone, I broke my old flip phone some years ago, by sitting on it. And I was upset about it obviously, it was a nice model then. I was student, bought it by saving for a while. Didn't have insurance and so on. And since then realized that it didn't make any sense for me to buy these expensive toys if they can easily be lost, stolen, broken _if_ it causes me so much anguish when happens. So since then I've bought used, or lower end smart phones (last one is a Moto G for $170 from 3-4 years ago) so that if it gets, broken, stolen, lost I wouldn't be too upset about it, just inconvinienced some, and would just go and buy another one. Kind of like buying another pair of pants or socks.
I one day if I win the lottery, maybe I'll be able to buy $500-$600 iPhones like that too. But today If I had one, and cracked or lost, I would be quite upset.
I am saying this because I've seen people sign contracts to buy these phones (which is basically getting a loan), buying insurance for them and so on, and all I am think "it sounds like you can't afford it". Can't obviously tell them that in person, but's that the idea.
Interesting. Different ways of managing expected frustration. Personally, I stick to highest-end phones I can afford, for the simple reason - I was once stuck for 3 years with a phone that was so crappy that it could barely lift its own OS - fire up any app, homescreen gets killed to save memory. Somebody calls you? 25% chance that you won't be able to pick it up, because the phone will hang. Try and turn on Internet on it? If you didn't turn off sync, you'll have to powercycle the phone by removing its battery to get it working again.
I don't break or lose phones often (in the last 3 years, I managed to crack the screen of my S4 two times; got the glass replaced both times for relatively little cost). But I use them quite a lot, every day. Minor frustrations like apps crashing, hanging, or taking 30 seconds to load tend to add up into quite a bit of frustration daily. So I prefer to save up and buy a phone that I know will work flawlessly for the next 3 years or so (and, like with S4, then I happily give it away to someone when I buy a new one; they can probably squeeze 3 more years off it too).
In my experience, buying these phones offers a better experience than many of the flagship Samsungs which suffer from bloated, slow and unintuitive software.
[0] https://community.rapid7.com/community/infosec/blog/2015/11/...
[1] http://www.howtogeek.com/218851/how-to-enable-always-on-vpn-...
1) PIN/TouchID locking of contacts, like you can do with notes. Don't allow messages and emails to and from the contact to be decrypted from the encrypted store without authenticating, like you can now do with notes. Would help with securing communications with legal counsel or other privileged parties from being captured.
2) A "duress" PIN/TouchID registration; if I unlock my phone with a duress code or imprint my duress-coded fingerprint, reboot the phone (to look like it was a glitch-induced reboot) and present the PIN prompt again. Auto-wipe the phone if the duress code is given again this second time.
If such a feature was commonplace, criminals would know about it and wouldn't be happy when they saw you activate it with your middle finger (I mean, who wouldn't use their middle finger to activate such a function!?) after they just threatened you enough to make you attempt to unlock your phone.
Besides, no criminal cares about your phone being unlocked. They just want the phone. Well, I guess there are circumstances where a criminal wants information, but if they're the ones compelling you, you have other pressing issues that go beyond protecting information from unauthorized parties.
I'm talking about being compelled to unlock your phone by someone seeking information on it, either depriving you of due process or your civil liberties.
This, as opposed to a passcode-only configuration, which a court order cannot compel you to give (I believe since this would fall in the category of 'forcing you to testify against yourself').
If that is indeed the case, I imagine it would make better sense to leave Touch ID disabled, unlike what this article suggests.
Court decision from 2014.
http://www.theatlantic.com/technology/archive/2016/05/iphone...
First known application since then.
Hidden containers similar to what TrueCrypt could do might take you farther in this regard. Self-destructing a hidden container should ideally not expose what you wish to protect and at least provide plausible deniability.
Contempt of court can basically be "get into jail indefinitely" card.
From the wiki: "The civil sanction for contempt (which is typically incarceration in the custody of the sheriff or similar court officer) is limited in its imposition for so long as the disobedience to the court's order continues: once the party complies with the court's order, the sanction is lifted."
It seems a judge can "choose" not to believe you. Whether they truly don't or not is another problem, but officially they can claim so. I am not sure if it takes another superior judge to get someone out of jail in that case or ... or just wait for the original judge to retire...
Another thing you could do is set it up with an unusual finger, like the middle-finger of your non-dominant hand. After five failed tries, Touch ID is disabled until you enter your passcode, so you can use the wrong finger five times when they ask you, and disable it that way. Say you're sweating too much or something (a common cause for real Touch ID failures for me).
It all depends on just how paranoid you are and what you want to defend against.
It entirely depends on your threat model. If you are at hacker or tech conferences, TouchID is far better as it can't be shoulder surfed. If your threat model is nation-states, then you would take a different approach. As TFA says:
> Turn the phone off before entering any situation that might lead to you being coerced to use your fingerprint to unlock the phone.
It's not too difficult to swap a home button yourself with the right tools, or most stores will do it for ~$49 to $59 (depending on your iPhone model.)
If you have a store do it, definitely ask for your original home button back in case you change your mind later or sell your phone.
You can always use a call relay. So you can give people one phone number that relays to your own real number (for voice calls) - although an voice call is obviously more vulnerable than Signal call etc.
Ditto, AFAIK there is the ability to setup a relay for SMS through an Android. I can't remember the app but basically people could SMS that number and it relays to you real number.
Before people jump on me, yes I am aware of the weaknesses of both of the above but sometimes a specific type of threat model requires these two tricks. I recommend it unless you are aware of the trade offs.
Ironically they got caught and I got the phone back.
Well, at least it prevents the thieves from doing more damage if it's stolen.
Using 3G or LTE wouldn't help someone trying to evade a state or higher law enforcement organization, since all they need to do is use the cellular provider's Lawful Intercept capability somewhere in the packet core, such as the GGSN (for metadata) or at a tower's next IP router (for call content).
I think the purpose of this guide was primarily for border crossings. Filippo almost certainly gets hassled at borders, as many security professionals do. His comment about the Great Firewall was more likely about accessing an unrestricted internet, and less as an phone call anti-surveillance measure.
That's in addition to the added attack surface that the root itself provides once the phone's up and running. Yes, the SU app on the phone (whatever that is nowadays) is supposed to prompt for permission before granting an app root access, but are you sure that code's bug free? Or free of intentional backdoors?
Some security settings that pertain particularly to Android devices only (such as ADB, internal SSH server) can only be disabled if you use apps that require root [0]. Maybe if you assume you have a targeted attacker, and they have physical access, root seems like a very bad target. If you install malware that gains root access, doubly so. But if the user is intelligent enough to not install random, non-vetted apps, and to turn auto-updates off, then rooting may actually provide a security benefit here, because you can at least avoid blind network attacks.
I'll also say that if you choose to unroot after using SecDroid [0], then you may find it difficult if not impossible to root the phone again, as you won't be able to use ADB anymore. In any case, there's a lot of vulnerabilities in mobile phones, and you really have to pick and choose to see which ones you think will most likely affect you.
You can always lock the bootloader again after installing your ROM. Unlocking it will wipe the device again which is inconvenient for ROM updates etc, but if you're a trooper, you can do it. This inconvenience was pretty easily fixed with the open source bootunlocker[0] apk which allowed to you unlock and relock the bootloader once in rooted userspace, but sadly it doesn't work on anything newer than the original Nexus 5 due to security features in newer Android hardware. Manual unlocking, re-installation and boot re-locking is still possible.
The decryption password can be beefed up with adb from the terminal as well. There isn't a pretty gui for it, but that way you can get a strong safe encryption password and a short screen unlock pin. Unfortunately the two are tied iirc normally. Some would argue that having an organically strong password is safer than allowing the hardware to help beef up weak pins.
I'm sure there are other problems, sadly Google seems to look at privacy and security on Android as issues for later. And running anything besides a nexus device is entirely less safe due to the toxic OEM/Google update environment.
http://bits-please.blogspot.com/2016/06/extracting-qualcomms...