Blockchain and Smart Contracts to Secure Property Transactions in Smart Cities

Cities have been growing at an impressive rate, and with the advancement of technology and digitization, new ways have been proposed to provide cities with a certain level of autonomy and intelligence so that they can self-regulate tasks that currently take a lot of time for both citizens and authorities, and which also have a negative impact on the environment. We have recently experienced one of the most abrupt changes in history as a result of the COVID-19 pandemic, where millions of people, businesses, schools, companies, governments, etc., have had to modify their ways of working, in addition to dealing with many other changes in the present moment, the most important of which is the transition to electronic transactions. This is a chance to progress toward smart city transformation and the implementation of models that assist citizens in their ordinary activities. One of the most common activities is the purchase of real estate. In this study, we propose a model to make the purchase and sale of real estate more equitable and fairer, and not just based on the amount of money. A smart home should be able to identify who its current owner is by functioning as an IoT badge, and, after the subject’s identity has been verified, it should be granted full access to all services, or else it should be blocked and/or alerted to the authorities. The use of smart contracts in a blockchain to transfer ownership of a smart home that includes, as inputs, those interested in acquiring a specific house and, as outputs, a person who chose the system based on the requirements previously established by the government of the Smart City. As a result, susceptibility to fraud or interference by a third person is reduced, and an individual’s security of living in a smart home, and therefore, in a smart city, is strengthened.