[tarekmoz]

zeromq is not secured - but they are working on adding security in the protocol.

In the meantime the safest way to avoid any security issue is to run IPC-only zeromq sockets or to set properly a firefwall and to use an SSH tunnel. There's such an option in Circus, where you can pass the ssh server to circusctl.

also, read up http://circus.readthedocs.org/en/latest/design/security