Re: SCADA

Paul D. Robertson wrote:
> The other side of the coin is that adding layers adds complexity and code- 
> and adding code adds bugs- so you don't *always* get a net security gain 
> by adding "protecion." 

You raise a problem that I've spent too much time pondering. In effect,
it refutes the "conventional wisdom" of computer security. Which goes
as follows:
Item #1 - Defense in depth is good
Item #2 - Complexity is the enemy of security

If #2 is true, #1 can't be, because defense in depth adds complexity.

Puzzled,
mjr.
-- 
Marcus J. Ranum		CSO, Tenable Network Security, Inc.
			http://www.tenablesecurity.com