ibenez wrote: ] The more secure a system, the less usable it is.  That is not necessarily a direct relationship.   Closer, and what your example was talking about:  The more secure a system, the less accessable it is. I have a great secured machine -- poured concrete blocks it from even being plugged in.  Worthless as a computer.  I have a fairly  secure machine -- a laptop in a safe deposit box.  Value of its data doesn't change day to day; might as well be one of the stock certificates stored with it.  I have a desktop with a firewall and a net connection -- every day it becomes just a little bit more  important to me.  Straightforward relationship and trade off. However, researchers have tried to demonstrate that usability is  critical for security -- see "Why Johnny Can't Encrypt" as an  example.  Security at the consumer level, at least, which is what  we're talking about in the context of Longhorn.  The value of a consumer-focused system is that which is created by the user.  If the user can't use it for value creation,  the security becomes less significant.   But if the security isn't usable, it won't be used.  Why does  everybody use public key cryptography when talking to Amazon, but  not in their email to their family?  Usability.  |