Abstract: A wearable data device, for being worn by a user to facilitate access to transactions and actions that require authorization by the user. The data device contains a memory unit for storing user authentication credentials for external devices. When an external device is detected that matches the stored credentials, the user authentication credentials are shared wirelessly and automatically. The data device has a removal sensor for detecting a removal event when the wearable data device has been removed from the authorized user. Upon the occurrence of a removal event the data device is automatically de-authorized and deactivated such that it must be again authorized before it will wirelessly share the user authentication credentials.