A system and method is provided for a distributed computing system where a user can login to a client computer and access a number of different applications installed on web servers. These applications are then provided access to data in mainframe systems without a user having to enter mainframe user id or password information for gaining access to the mainframe system. The system and method can utilize a sign on object which is installed onto the client computer. The sign on object operates to obtain and transmit a security token which authorizes access to the mainframe system, and the security token does not require the use of the cookie data. This system and method can pass the security token through the web server and the web application in an encrypted form which limits security risks.