Due to the Online Native Mobile applications architecture, it's essential to have a security mechanism to restrict access only to users authorized to the application data.
In this architecture, it's through REST Web Services that data updates (PUT, POST, DELETE) and queries (GET) are performed. That's the reason why it's so important to have a security mechanism to prevent that such actions are performed by not authorized users.
Through the configuration of Enable Integrated Security Property, you can automatically add security to your Native Mobile Application.
The security mechanism is automatically generated using the GeneXus Access Manager (GAM).
Once the property Enable Integrated Security Property is activated, same changes occur in the KB, see Creating the GAM repository for the first time from GeneXus.
My first SD application with integrated security enabled
GAM architecture for Native Mobile applications