Re: [CAD_CAM_EDM_DRO] Re: EMC security

[Jon Elson <jmelson-at-artsci.wustl.edu>]

> If you need to protect the system against inadvertent changing or
> removal of files, it's fairly easy. Protecting against determined
> hackers is more of a problem. Easy way:

Well, I actually think it can be pretty secure, assuming no gaping
holes are found in Linux, itself.  You can set the system up
so root accepts no remote logins, period, and the only thing
you can do remotely is ftp or telnet to one or two accounts,
and then only from one of your own, local, machines.  Set
networking so that no connects are accepted except from that
local machine, period.  that should make it fairly hard for
hackers to get in.  Now, if you only have ouside network
access on your other machines by dialup, and don't have
a gateway on that machine, the Linux machine is pretty safe
without much change.  If you have a gateway, or keep one
of your machines connected to the net all the time, you have
to take some precautions.  You can also set up your gateway
to prohibit any remote access to the Linux machine.  If you
want to make EMC-related files available outside, you would
need to move them to the 'public' machine.  This makes sense
anyway, as you wouldn't want outside demand for a file mentioned
on your web page to bog down the CNC control machine while
you were making parts.

Jon