A systemThis is a very generic term for any collection of components that, all together, can do something. Systems can be built from subsystems. Examples are your cell phone; your computer; the radio in your car; anything that seems like a "whole." of mathematical algorithmsA way of calculating something, typically as a step-by-step recipe. A familiar one to all of us is how we do long division on paper: that's an algorithm. Algorithms abound in the IoT. for public and private keysA key that should be known only by your device and, possibly, by someone or something else that your device is communicating with. It must be kept secret. as well as certificates of authority that are used when authenticating a web session.
Inside the Internet of Things - Bryon Moyer Blog