Amazon RDS for Oracle supports Kerberos authentication in additional regions

Amazon RDS for Oracle now supports external authentication of database users using Kerberos and Microsoft Active Directory in additional regions. This feature provides the benefits of single sign-on and centralized authentication of Oracle Database users. Keeping all of your user credentials in the same Active Directory will save you time and effort as you will now have a centralized place for storing and managing them for multiple DB instances.

Source:: Amazon AWS