A user device initiates a network access authentication operation via a network access device with a network access authentication server, e.g., a Remote Authentication Dial-In User Service (RADIUS) server, which also generates an X.509 proxy certificate and includes the proxy certificate with the information, such as a set of network access parameters, that is returned to the user device in response to a successful completion of the network access authentication operation. The user device extracts and stores the proxy certificate. The network access parameters are used by the user device to communicate via the network access device on a network, which supports a grid. When the user device accesses a resource in the grid, the proxy certificate is already available, thereby obviating the need to generate a new proxy certificate and allowing a user of the user device to experience an integrated single-sign-on for network access and grid access.