The blockchain is a new technology that is breaking through in many fields, and also in the educational system. But it is not a specific technology which you can expect to improve a concrete situation: It is more a technology that allows registering events from an innovative form. And this can be translated into unsuspected changes. After presenting what Blockchain is and some examples of social uses, in the applications currently in use, there is an analysis of the problems to which the technology aims to answer. A review of the most outstanding experiences, all in an early phase of development, leads us to some critical conclusions about its viability.