Security and API implementation - REST

I'm implementing an API using Django. One 1 service should be able to access 1 API url.

I am wondering if there are any popular security practices that go beyond using username/password and SSL?

Is using sequential signature generation a popular practice?

You could try to use django-piston. It uses OAuth for authorization.

do not forget this Django REST framework:

django-rest-framework.org

I switched to this framework after trying tastypie for a while.