  The paths leading to future networks are pointing towards a data-driven
paradigm to better cater to the explosive growth of mobile services as well as
the increasing heterogeneity of mobile devices, many of which generate and
consume large volumes and variety of data. These paths are also hampered by
significant challenges in terms of security, privacy, services provisioning,
and network management. Blockchain, which is a technology for building
distributed ledgers that provide an immutable log of transactions recorded in a
distributed network, has become prominent recently as the underlying technology
of cryptocurrencies and is revolutionizing data storage and processing in
computer network systems. For future data-driven networks (DDNs), blockchain is
considered as a promising solution to enable the secure storage, sharing, and
analytics of data, privacy protection for users, robust, trustworthy network
control, and decentralized routing and resource managements. However, many
important challenges and open issues remain to be addressed before blockchain
can be deployed widely to enable future DDNs. In this article, we present a
survey on the existing research works on the application of blockchain
technologies in computer networks, and identify challenges and potential
solutions in the applications of blockchains in future DDNs. We identify
application scenarios in which future blockchain-empowered DDNs could improve
the efficiency and security, and generally the effectiveness of network
services.
