Also, there is a draft being working on for credentials transfer:
This document describes a mechanism to transfer digital credentials
securely between two devices. Secure credentials may represent a
digital key to a hotel room, a digital key to a door lock in a house
or a digital key to a car. Devices that share credentials may belong
to the same or two different platforms (e.g. iOS and Android).
Secure transfer may include one or more write and read operations.
Credential transfer needs to be performed securely due to the
sensitive nature of the information.