title: How do MPI implementations (OpenMPI, MPICH) handle security/authentication
body: <p>How do OpenMPI and MPICH handle security when I send MPI messages between the processes over TCP/IP sockets?</p>
  
  <p>In particular, how do they prevent other users of the same network from connecting to a listening socket and sending fake MPI messages?</p>
  
  <p>The specific scenario is the following:</p>
  
  <ul>
  <li>The administrators are trusted. Untrusted users do not have a physical access to any hardware or network. Untrusted users do not have root access.</li>
  <li>However, untrusted users can run their own programs in the cluster; the cluster nodes are typical Linux boxes. In particular, untrusted users can open TCP connections from any machine to any other machine in the cluster and send arbitrary messages.</li>
  </ul>