Archiva uses the Redback security framework for managing repository security. When the server is first started, you will be prompted to create an administration user. This user will be given permission to administer all aspects of the system (as well as access to all of the repositories). This user can then be used to grant permissions to other users.
A guest user is also created by default, and given read access to the default repositories (internal and snapshots). Repositories with guest user access can be accessed without the use of a username and password (or without being logged in to the web interface).
The ui provide a screen to manage your users. You can:
NOTE: you can disable user registration using UI configuration