Xiaomi MIUI Pure Mode Can Optionally Block Sideloading Android Apps
Android's openness doesn't come without a price, and one of the most cited costs is security. Unlike Apple's walled garden, Google has a hard time completely disallowing the installation of apps from third-party sources via APKs. The Android maker could only encourage developers and users to patronize the Google Play Store, but the final decision is ultimately in users' hands. Xiaomi, however, might be testing a way to give Google a hand with an MIUI Pure Mode that makes it a bit harder to sideload those apps.
Google will probably never be able to close that sideloading door on Android, especially since it would be possible to create third-party ROMs that would allow that experience anyway. In fact, some manufacturers, including Samsung, have their own app stores that depend on this functionality, though in a more sanctioned manner compared to, say, the F-droid open source app repository. That said, even those OEMs are keenly aware of how the open mechanism can sometimes work against them if users aren't aware of the dangers they pose.
Xiaomi is apparently working on a Pure Mode for its custom MIUI Android experience that adds some protection on top of Android's security model. Android already warns users about installing apps from third-party sources by default, but it is almost too easy to bypass that by tapping through the warnings. MIUI Pure Mode might enforce that policy and let users intentionally disable it if they want to and at their own risk.
Pure Mode, however, does have another key element that is both more subtle and probably more critical. It will block any installation process that happens in the background, which is often the method employed by malware developers and hackers.
As always, this Pure Mode can be disabled, though the information doesn't mention if the two features can be controlled independently of each other. The feature is currently in beta testing in China, and there is no word yet on whether it will make it to the global MIUI version in the long run.