Blockchain technology is born in 2008 to validate Bitcoin transactions, the first and most popular cryptocurrency. Its development has been initially correlated with its original purpose, but being an algorithm with high cybersecurity potential, in the last years it has become more and more interesting for many other fields of applications. Blockchain can have a key role in the progressive digitalization of goods and services, its versatility is greatly appreciated by programmers and companies have started to invest in this technology. Many applications are now consolidated or in advanced phase of study. On the other hand, blockchain is characterized by a high energy cost caused by its protocol of validation, called Proof-of-Work.