  Direct Mobile-to-Mobile communication mode known also as Device-to-Device
(D2D) communication is expected to be supported in the 5G mobile system. D2D
communication aims to improve system spectrum efficiency, overall system
throughput, energy efficiency and reduce the connection delay between devices.
However, new security threats and challenges need to be considered regarding
device and user authentication to avoid unauthorized access, abuse and attacks
on the whole system. In this paper, a strong standalone authentication
technique therefore is proposed. It is based on combining users biometric
identities and a new clone-resistant device identity. The novel property of the
proposal is that it is fully independent on both device manufacturer and mobile
system operator. The biometric identity deploys user keystroke dynamics and
accelerometer to generate user biometric identity by deploying a machine
learning technique. The proposed mobile device clone-resistant identity is
based on deploying a new concept of a pure digital clone-resistant structure
which is both manufacturer and mobile operator-independent. When combining both
identities, a mutually authenticated D2D secured link between any two devices
can be established in addition to a strong user-device authentication.
Furthermore, the concept does not allow the managing trusted authority to
intercept users private links. Being an independent and standalone system, the
technique would offer a broad spectrum of attractive future smart applications
over the 5G mobile system infrastructure.
