It would help to watch your belongings while in the world. You want to be someone other than the person who loses their wallet, leaves their car unlocked, or remembers to lock the door before leaving. What about your computer? Are you sure that no one can see what you're working on when you use it at work? Do you know what those apps are doing in the background or if they're safe to use at home? A trusted computing base (TCB) is like a bodyguard for your computer. It watches over all of its hardware, firmware and software components and ensures they're all on the up and up and that nothing's going on behind your back. It enforces security policies to ensure the system's security and its information. System safety is achieved by provisioning methods like controlling access, requiring authorization to access specific resources and enforcing user authentication. The TCB is like a house. It would be best to build it on a solid and secure foundation. But even if you make it with the best materials and use the most advanced construction techniques, it will only be swift if your house is protected from intruders. So what does this mean for your computer? It means your computer has a TCB (or "Trusted Computing Base"), which can be secured even if you aren't using other security measures. If someone breaks into your house? Well then, even if they don't take anything of value, they've still made themselves home in your kitchen! Who knows how many crumbs they left behind? The same goes for computers. If someone gets into your computer without using any external tool or solution, they've broken into your TCB, and now they're free to leave all sorts of crumbs behind them!