Follow-up of Apple disabling udid

The udid itself is harmless and does not carry any personal information of the user, but developers can combine it with the information gathered in the application to track user behavior. If it is prohibited, it will not only affect the advertising network, but also the app developers who wish to bring a better user experience. The disabling of udid will lead to many problems. Of course, Apple will provide alternative solutions, but can the problem be solved?

Apple released a report in February this year. We recommend that developers disable udid. In fact, it is not a bad thing for a developer to tell the user through udid to use the developer's application on a certain device. For example, developer David Barnard only uses udid to synchronize app Cubby applications from one device to another. If the server cannot distinguish all devices, everything will be messy and developers will not be able to provide users with synchronization services.

Another example is the popular Twitter app tweetbot. It uses udid to identify the device to which the message is sent and the device has received the message. If there is no udid, applications cannot be distinguished. Therefore, the problems around udid are not only the problems faced by the advertising network and tracking users' sales products, but also various other problems.

The developer wants to install an application in a certain environment without advertisement. it is valid on the device, and Apple knows that it needs to provide other options for developers. Therefore, cfuuid (core Foundation universally unique identifier) is recommended ).

But not every application can use cfuuid very well. This is not a good alternative. Cfuuid is activated only when the app sends a request to the IOS system. The developer can leave it somewhere, but it may be deleted and cannot be retrieved. However, once the udid is activated, it will permanently exist on the device.

Paul Haddad from tweetbot studio tapbots said:

"Cfuuid has many problems. If you Back Up Files from an old device to a new device, the two devices will have the same cfuuid. If you back up the operating system from a temporary file, different cfuuid will appear in a device ".

Of course, in addition to cfuuid, there are other solutions, but there are also limitations. For example, a MAC address (that is, the network hardware ID of a device) is used, but it is permanent like a udid and cannot be accessed by the network administrator.
Hackers usually identify the location of a user's device through the MAC address. If Apple disables the udid, the MAC address may be disabled next. Haddad said:

"If you want to track a device in a foolproof way, there is no more suitable option than udid. When people want to thoroughly clean up, store, and update devices, the lack of udid will pose many difficulties for developers. Disabling udid is not only an impact on the advertising network and those who use udid to track user behavior and make profits, but also an impact on developers who want to bring a better user experience ".

Of course, there are other solutions, using the current udid or MAC address and app ID for encryption, as each application, each device's independent serial number, however, this method does not work to track users among multiple programs. openfeint and appfire use the login System in the application ecosystem as an alternative, however, this method is not applicable to every application. Http://www.weiphone.com/apple/news/2012-03-27/Apple_disabled_UDID_follow-up_421797.shtml bygqzhu