Software as a service; platform-as-a-service; providing virtual machines for cloud computing; all the aforesaid relating to systems to control access to restricted areas; software as a service enabling access to cloud-based locking systems (smart locks); user authentication services with login technology for online software applications; user authentication services using blockchain technology; development; appearance; updating and maintenance of computer programs (software); design of prototypes; design and development of new products, in relation to the following fields: access control to restricted areas