  The combination between innovative topics and emerging technologies lets
researchers define new processes and models. New needs regard the definition of
modular and scalable approaches, with society and environment in mind. An
important topic to focus on is the smart city one. The use of emerging
technologies lets smart cities develop new processes to improve services
offered from various actors, either industries or government. Smart cities were
born to improve quality of life for citizens. To reach this goal, various
approaches have been proposed, but they lack on a common interface to let each
stakeholder communicate in a simple and fast way. This paper shows the proposal
of an architecture to overcome the actual limitations of smart cities: it uses
Blockchain technology as a distributed database to let everyone join the
network and feel part of a community. Blockchain can improve processes
development for smart cities. Scalability is granted thanks to a context-aware
approach: applications do not need to know about the back-end implementation,
they just need to adapt to an interface. With Blockchain, it is possible to
collect data anonymously to make some statistical analysis, to access public
records to ensure security in the city and to guarantee the origin of products
and energy.
