I’m currently doing some research about my project, a smartphone tracking native application, and I have four questions. Links to any material I can read up will be greatly appreciated, and the most useful/comprehensive response will be accepted.
The primary target smartphones are the Android, Blackberry and iPhone models.
For starters I found out here Uniquely Identify an Android Handset that IMEI can be used to uniquely identify Androids but I think I once read that it can be faked. I don’t know about the iPhone and Blackberry.
- What’s the most reliable way to uniquely identify the smartphone device, if any? Can MAC addresses work or is it possible to spoof that? Can IMEIs truly be faked?
- Is it possible to “lock” the device with a custom error message remotely via its unique identification, once the device is reported as stolen? This lock state will remain on the phone even when disconnected from the network, until it is reconnected to the network and unlocked remotely once again.
- Assuming such a remote phone lock is possible, can such be reversible by the thief? The native app will run in stealth mode so that it cannot be uninstalled.
- Can a cross-platform solution work in this case, or will I have to develop various native apps per platform?
EDIT:
Some more context. As Till rightly said, Apple’s “Find my Phone” does this exact thing already (I am just finding out about it, but it looks like a perfect fit already). The user who is choosing to install the app is informed that the phone will be uniquely identified if they do install the app. As for locking the device, “Find my Phone” does it (I gather). Now I need to know how that might be possible on the two other platforms.
Only the network operators can talk to the handsets on an IMEI level. The IMEI number IS the MAC address of GSM networks. However, you can’t access that unless you have control of the network. Sure you can get the IMEI from the user, but you can’t use that to locate the phone. On CDMA networks this address is called the MEID number.
But there are other ways:
You can get location data on either platform with the users’ permission. This is the way you should think about developing your application. You’ll want to assign a UUID to a user once they download and install your application on their phones. You can then have the phones report to a server every so often (heartbeat). As long as the phone is powered on and connected to a network, the user would be able to locate the phone.
You can also get the phones IP address on the network, among other things — such as contacts, messages, files, cache data etc..
On Android it’s pretty easy to implement this kind of functionality as a service that could would only be visible on the packages page. Further, if you have root access, you can write whatever kind of rootkit you want such that it hides itself from the system. Same with a jailbroken iPhone. I am not as knowledgeabe about iPhone services though.
Either way, the only cross platform compatibility you’d be able to exploit would be perhaps the way data is sent and received from the server. You could use some standard such as JSON to send and receive data (and hence the same server). Although, both platforms have JSON and Apache libraries, the other parts of the apps or services themselves will need to be completely and dependently developed for each platform (UI, Internal Content Handeling, Syscalls, Permissions, etc).
You can remotely lock, wipe, factory reset, etc. Android devices using the security and device administration Android system interface. This still requires the user to grant permission and it asks them an a more.. obnoxious.. way so that they know what exactly they are agreeing to when they give an app device administration permission. If you ever use an exchange server for business or school, it’s likely you’ll run into this.
I am unsure about remote iPhone device administration on a jailed system.
If you really want something that can’t be removed lest you do a factory reset, you’ll need to know a thing or two about Unix programming, and a lot about the operating systems that their respective SDK’s don’t (and probably shouldn’t) tell you. You’ll need to be comfortable poking around sources and even reverse engineering if called for. If you’re still interested, you’ll want to hang around the circles that work on custom phone firmware and software for the iPhone, and Android (and Blackberry). I would start with Android. It’s probably the easiest since the sources for the AOSP are easily and legally available.