CollabNet TeamForge APIs use a shared secret key which the Subversion Edge server needs to communicate with the TeamForge site.
If your TeamForge installation is hosted, contact CollabNet Support to get this key. Otherwise, follow these steps:
Open the sourceforge.properties file located in /runtime/conf in your TeamForge site directory. For example, /opt/collabnet/teamforge/runtime/conf/sourceforge.properties.
Note the value of the property sfmain.integration.security.shared_secret.