title: How To Determine Unique Device ID in IOS apps
body: <p>I have been doing some research on UUID for the iPhone and see that apple is not using that and opting for some new method which I do not totally understand</p>
  
  <p>What I am trying to achieve is to offer a level of security for people who are tracked via my app</p>
  
  <p>Scenario</p>
  
  <p>new client Susan purchases my device which is trackable via an iPhone app I have developed (the device that is tracked is not a phone its a dedicated gps tracker that reports its location to a server)</p>
  
  <p>Client Susan wants Mary to be able to track the device via the iPhone app </p>
  
  <p>Susan tells Mary to download my app</p>
  
  <p>My client Susan is able to addd Mary's details name to our tracking database with a table allowed app users, without this information the app Mary downloads will now show the location details of Susan's device.</p>
  
  <p>So I need to have some stored value that identifies Mary each time she opens the app its passed to the web service to retrieve the list of device Mary has been granted access to potentially not just from Susan. (Mary may be a community care worker responsible for different clients in the community and the family of those different clients each grant Mary access to the tracker their family have bought)</p>
  
  <p>The first logical solution is to uses Mary's email address due to it being unique however there is a security risk that others who download the app for free, should they know Mary is also an app. user by them entering in Mary's email address they will grant them access to all the devices Mary has access to given the app will display all devices listed in the database that have Mary's email address assigned to it</p>
  
  <p>So this brings me to the UUID value of the ios device which apple has canned, I need to be able to display a unique device id (device imei number would work) so that when Mary loads the app the unique value is displayed and its that value that Susan will need to register along with Mary's details to grant Mary access to the device, if others want Mary to access other peoples devices Mary needs to provide them this same unique id which others will use to register mary's details against the other devices</p>
  
  <p>IF the device is rebooted and the app is reinstalled then the same device id would be read from the device without them needing to re set-up access as would be the case if the unique device id was dynamically generated by my app</p>
  
  <p>So can you advise what the best approach is to the above give that the traditional UUID is no longer allowed by apple</p>
  
  <p>Kind Regards</p>
  
  <p>Claude Raiola</p>