Yes. get the document on CWP:
Custom Web Publishing enables you to restrict access to your published databases through database password protection, database encryption, and secure connections. When using a Custom Web Publishing solution to access a database, web users may be prompted for their account information. If the Guest account for the database is disabled or does not have a privilege set enabled that includes a Custom Web Publishing extended privilege, the Web Publishing Engine uses HTTP Basic Authentication to request authentication from web users. The web user’s browser displays the HTTP Basic Authentication dialog box for the user to enter a user name and password for an account that has a Custom Web Publishing extended privilege.
... and more.