Several iPod touch, iPad and iPhone users reported the following error message when attemting to access the iTunes or App Store: The certificate for this server is invalid. You might be connecting to a server that is pretending to be “itunes.apple.com” which could put your confidential information at risk.
To fix this issue, please make sure you set your iPad, iPhone or iPod touch to the correct date and time. To verify, tap Settings > General > Date & Time. Then toggle on “Set Automatically”. Further make sure that your time zone is set up correctly. Simple tap Settings > General > Date & Time > Time Zone to verify this.
If you notice that the incorrect date, time, or time zone is being set up automatically on your iPad, iPhone or iPod, tap General > Date & Time and turn off Set Automatically. Then set the correct time and time zone manually.