actually security is not a feature, but a constraint. It doesn't bring the user anything, but it absence would be a problem for secondary reasons (that might be important in the grand scheme of things).
Imagine a bank (well just an account), on the functional level, you just need to deposit and withdraw money. The fact that they have to secure it is a huge constraint, but at the functional level we're not far from a trash can, a parking lot or a gas tank.
Imagine a bank (well just an account), on the functional level, you just need to deposit and withdraw money. The fact that they have to secure it is a huge constraint, but at the functional level we're not far from a trash can, a parking lot or a gas tank.