https://en.m.wikipedia.org/wiki/Society_for_Worldwide_Interb...
Besides that article's subject, it has enough links to keep you busy for months. Be sure to read the "Security" section.
"Banking" is a huge subject. If you really want to learn (part of) it, best would be to find an area that interests you, and work in it. That's one of the best parts of programming, it's not really about programming, it's about the industries that use it.
As for "key words," I think better is to follow links, and soak in any keywords that gradually come from what you find that's interesting.