9.5 Horizontal Propagation
In horizontal propagation, the Subject containing the security attributes are propagated amongst the front-end WebSphere Application Servers. The default Single Sign-On token is LTPAToken version 2. We can create your own custom token and add that to the Subject in a custom Login module. The token contains the following information:
The users unique ID.
Timestamp.
The key to lookup the serialized security attributes.
The originating servers' JMX Administration endpoint which tells the receiving server how to communicate with it. During the WebSphere Application Server Initial Login process, the Single Sign-On token is added to the Subject and the token is added to the HTTP response as a cookie. This Login process can also be customized to add custom information to the Single Sign-On token or to the Subject by using JAAS Login Modules. If you have horizontal propagation enabled, it enables the front end receiving servers to retrieve the Subject information and extract the security attributes information from the Subject. In this case, Initial Login occurs at the originating server and propagation login occurs at the receiving servers.