  5G mobile networks provide additional benefits in terms of lower latency,
higher data rates, and more coverage, in comparison to 4G networks, and they
are also coming close to standardization. For example, 5G has a new level of
data transfer and processing speed that assures users are not disconnected when
they move from one cell to another; thus, supporting faster connection.
However, it comes with its own technical challenges relating to resource
management, authentication handover and user privacy protection. In 5G, the
frequent displacement of the users among the cells as a result of repeated
authentication handovers often lead to a delay, contradicting the 5G
objectives. In this paper, we propose a new authentication approach that
utilizes blockchain and software defined networking (SDN) techniques to remove
the re-authentication in repeated handover among heterogeneous cells. The
proposed approach is designed to assure the low delay, appropriate for the 5G
network in which users can be replaced with the least delay among heterogeneous
cells using their public and private keys provided by the devised blockchain
component while protecting their privacy. In our comparison between
Proof-of-Work (POW)-based and network-based models, the delay of our
authentication handover was shown to be less than 1ms. Also, our approach
demonstrated less signaling overhead and energy consumption compared to peer
models.
