Accessy's security is based on the identity contained in the app. It is a certificate that is exhibited and stored in the mobile's secure space. This is where the analogy with Mobile Bank ID is found, because the corresponding technology is used.
When a door is opened, the transaction is signed by the certificate and all communication is encrypted. That way, the service keeps track of which key opens the door. When logging in to the portal, the app is used to identify the user. Here, too, is the analogy with Mobile Bank ID. The difference is that Accessy uses mobile phone numbers as identity instead of social security numbers.