What is this kind of crypto called?

[Kurt Granroth]

On Tuesday 04 April 2006 13:05, Craig Brooksby wrote:
> I once read of a python library for creating a certain type of
> cryptography.  I've forgotten the keyword for this kind of crypto and
> so I can't find it!
>
> What I'm talking about:  You encrypt a file, and generate three keys,
> and give a key to each of three people.  No single key can open the
> file.  It requires *any two* of the three keys to open it.
>
> What's the term for this?  Not "federated?"  Is "escrow" in there
> somewhere?  Can one of you crypto-spook types help me name what I'm
> looking for?

Is this what you are talking about?

http://www.nightsong.com/phr/python/crypto.txt

FWIW, I don't think I've ever heard a term for that process other than just 
"key splitting"

Kurt