Question about the pear blowfish class

Can anyone explain this to me please - not the algorythm but the
implementation?


What is the defaultKey there for and how does my own key override it?
What is the"vector.txt" file and how or when is it applied.

As I dont use pear I've stripped out all the pear functions and calls
and the utility works fine on my windoze box.

I dont understand the above at all though - can anyone explain please?

tks

tony