I would like to obtain encypted data over a network in real-time. The
nature of the data and process is as follows...

A physical hardware device is located at some remote location. When the
sensor gets activated, it must notify an operator at a remote facility
within seconds (probably no less than 2 seconds). The device is
attached to some computer system by a network and will transmit various
types and amounts of data once the device is activated. This data must
be encrypted with some very high and secure encryption method. If
someone were to decrypt the data during its real-time transfer, it
could result in an unimaginable catastrophic event (including death to
people).

Once the client application receives the data, it must present it on
the screen instanteously (virtually no delay) so that action can be
taken.

Obviously, the use of the Internet is ruled out because the Internet
cannot deliver real-time (or even close to the speed I require). Even
so, the nature of the application does raise some interesting
questions:

1. Given a dedicated and secure network, would Internet technologies
(using TCP/IP, etc.) be suitable for this type of application? Or...
2. Would a dedicated client/server based on some proprietary network
protocol significantly outperform a TCP/IP based application?
3. If the application is based on .NET, does .NET provide enough
security services to handle this type of application?
4. Would an application written closer to the machine level rather than
going through a layer such as the CLR give significantly higher
performance (in other words, don't use .NET but write stand-alone C++
applications)?
5. Assuming that a private network (Intranet) based on TCP/IP could be
used, could a browser-based app be used? The question here is whether
it is possible for the remote system to notify a browser application
without the browser app having to poll the remote system.
6. Have you ever come across an application of this nature and if so,
what OS was it using and what programming language/technologies did it
use?

Using TCP/IP technologies definitely does have a benefit because it
does allow the system to expand and interact with a huge host of
applications that deal with this technology. Under some conditions, it
may even be permissable to transmit some of this data over a public
Internet and therefore being more native to the TCP/IP world would make
things more compatible (although at the higher risk of being
intercepted and decrypted).

Thank you for your insight
Johann