Comment by jfengel

The Internet and Web were both designed with the assumption of cooperation. I wonder what they would have built if they'd taken hostility into account from day one.

As we've seen security is really hard to build in after the fact. It has to be part of your design concept from the very first, and pervades every other decision you make. If you try to layer security on top you will lose.

Of course you may discover that a genuinely secure system is also unusably inconvenient and you lose to someone willing to take risks, and it's all moot.