The upcoming iOS 11.3 software update will bring increased security when connecting third-party MFi-certified USB accessories to an iPhone, iPad or iPod touch.
Specifically, for a locked iOS device to communicate with USB accessories the user will need to either connect an accessory to their unlocked iOS device via the Lightning connector or enter their device passcode while connected, at least once per week.
“If you use iAP USB accessories over the Lightning connector or connect to a Mac or Windows PC, you may therefore need to periodically enter your passcode if you have a passcode set on your iPhone, iPad or iPod touch,” Apple explains in the iOS 11.3 release notes.
This change also affects wired CarPlay and assistive devices.
For those wondering, iAP stands for the iPod Accessory Protocol, which is what third-party accessories can use to access advanced features of Apple devices, like the ability to communicate securely with iOS apps through the iOS External Accessory Framework.
To incorporate iAP into their design, the accessory developer must be a member of Apple’s “Made for iOS” (MFi) licensing program and integrate specific MFi hardware into the accessory.
Apple has been tightening the security of iOS lately.
iOS 11.0 increased pairing security by requiring a passcode for the “Trust This Computer” prompt that appears upon attaching an iOS device to a computer for the first time via USB.