IFC is orthogonal to type systems, having also been modeled in terms of axiomatic semantics (Hoare logic) independent of a type system. It can also be practically implemented through runtime monitoring, partial evaluation and various hybrid approaches. Type systems are certainly one way of providing foundations for IFC, but few languages have it as a first-class construct. Notable exceptions are SPARK (based on Ada) and Jif (based on Java).
Interesting, I'll definitely have to check this out. Any input on whether this has been applied and/or could be applied to actor paradigms of computation?
It seems like modeling data flow via messages would be pretty natural semantics for something like this. But first I need to dig into what Hoare logic is and how it applies.
I've always considered the primary purpose of type systems to be restricting how data can flow through a program.