Apple has informed that they would no more signs the older versions of iOS 11, under iOS 11.2.3. It was after which the company had launched iOS 11.2.5 on Janaury 23, which Apple decided stopping signing older versions. It means that general public can no longer downgrade to older versions under iOS 11.2.5. However, developers and public beta testers are free to download iOS 11.2.3.
The new decision came on the wake of Apple’s intention of encouraging customers to keep the latest OS. With iOS 11.2.5 already becoming much a popular one amongst Apple user community, the decision might not find much hassle.