A system for user authentication includes an authenticated device with a restricted-access function that a user is able to access in response to verification of an identity of the user by the authenticated device and a proximate device with a restricted-access function that the user is able to access in response to the proximate device receiving authentication data that includes the identity of the user from the authenticated device. The authenticated device is operable to identify an absence of intent of the user to access the restricted-access function of the proximate device, and in response to identifying the absence of intent to access the restricted-access function of the proximate device, emit a locking signal such that, in response to detecting the locking signal, the proximate device enters a locked state and the restricted-access function of the proximate device is inaccessible to the user.