  Traditional user authentication involves entering a username and password
into a system. Strong authentication security demands, among other
requirements, long, frequently hard-to-remember passwords. Two-factor
authentication aids in the security, even though, as a side effect, might
worsen user experience. We depict a mobile sign-on scheme that benefits from
the dynamic relationship between a user's attributes, the service the user
wishes to utilize, and location (where the user is, and what services are
available there) as an authentication factor. We demonstrate our scheme
employing Bluetooth Low Energy beacons for location awareness and the
expressiveness of Attribute-Based Encryption to capture and leverage the
described relationship. Bluetooth Low Energy beacons broadcast encrypted
messages with encoded access policies. Within range of the beacons, a user with
appropriate attributes is able to decrypt the broadcast message and obtain
parameters that allow the user to perform a short or simplified login.
