In reply to Chris Sistrunk.

Thanks Chris, as you rightly said, "end users are very slow to adopt
secure authentication". This is because of the nature of the utility
industry. Also not all legacy devices will get updates from vendors and
with equipment upgrade cycles where 15 - 20 years is quite common, the
best way to protect communications is by introducing network based
security measures such as Firewalls, IPS, IDS. This not only secures these
critical infrastructure devices as also makes it easier to manage security
across an array of different vendors.