Comments by Member 879724 (Top 1 by date)

To achieve possibly role based security for Web services. You can even use claim based authorization technique. You can follow below steps to achieve this:
1. Configure system to use Kerberos Authentication
2. Implement claim based Role Based Authorization Model. Follow below steps
a. Keep one repository for storing Role in an organization
b. Develop custom Role provider(Refer above article for this)
c. Develop a custom principal object (Organization specific) which can be configure at a custom authorization policy