Apple stops signing older code following iOS 11.3.1 release
Following last week's release of iOS 11.3.1, Apple on Wednesday stopped signing legacy iOS 11.3 code in a strategy designed to ensure iPhone, iPad, and iPod touch owners are running the most up-to-date version of the mobile operating system.
As it does with every new release, Apple ceased code signing of iOS 11.3 following the release of iOS 11.3.1, which went live last Tuesday.
Along with a few minor bugs, the latest iOS version fixed a problem in which some iPhone models, specifically iPhone 8 devices, were rendered unusable after undergoing third-party display replacement. The issue cropped up earlier this month with the release of iOS 11.3, with some users reporting aftermarket iPhone screens failed to respond to touch input.
Apple regularly stops signing code in an effort to prevent users from installing old iOS versions. In addition to system security, restricted code signing helps ensure users have the most up-to-date firmware running on their iPhone, iPad and iPod.
The company is currently beta testing iOS 11.4, which promises AirPlay 2 support, Messages in the Cloud integration and Apple's new ClassKit framework.