OT protocol security¶

Most OT protocols were designed in an era when the network carrying them was assumed to be physically isolated and operationally controlled. Authentication was unnecessary because strangers could not reach the wire. Encryption was unnecessary because the data was process telemetry, not state secrets. That assumption has eroded, and the protocols have not changed as fast as the networks they run on.

The pages here cover the security properties each protocol was built with, the gaps that follow from those design choices, and the compensating controls available when the protocol itself offers nothing.