[woodruffw]

There are all kinds of different adversary models: these kinds of algorithms are tailored towards IoT or short-term communications use cases, where size and performance on constrained devices are more important than being secure against a nation state for X years.

For example: you may have a “smart” device in your household that indicates whether you’re home or not. You don’t want a passive adversary to be able to snoop its RF traffic, but you also don’t need its traffic to be secure for more than one week. “Lightweight” algorithms are meant to give you formal guarantees around that, while also balancing performance, power consumption, and other interests.