All, I have added support to allow the HPC Basic Profile Compliance Tester to identify clients via X.509 (instead of just username/password). The service's URL is https://opteron4.cs.virginia.edu:45885/FormServerTemplates/HPCBasicProfileCo mplianceTester.aspx. On the left hand side, you will now see a radio button labeled "Client authentication". It has 2 options, "Username/password" and "X.509". If you select "Username / password", the username and password boxes will function as before. If you select "X.509", then those boxes will be disabled and the compliance tester will attempt to make a mutually-authenticated SSL connection to your service. The certificate that the compliance tester uses is available at http://www.cs.virginia.edu/~gsw2c/HPCBasicProfileComplianceTesterCert.pem. If you want to test your service's X.509 authentication, download and install this cert where ever it needs to go so that your service will trust the HPCBP Compliance tester. This is a self-signed cert that will expire about a week after SuperComputing. Please let me know if you have problems. Glenn