the cross keys are mainly used as a pseudo catholic symbol of st. paul.

you will also find a few other esoteric groups and concepts use them, though they are somewhat divorced from the origin of the symbol.

All symbols can (and should) be deconstructed to ascertain what they were originally depicting. the keys (and many others) have survived the passage through time (millenia in fact) and while they still hold their original meanings within them, they gained new "meanings" along the way and few realise what they actually depict.

The cross keys originally symbolised a dualistic concept. The rods of the keys form a cross, which implies the interaction of two seperate axes each with two polarities. The rods depict ying/yang - light/dark - male/female, etc..

each rod however has two polarities - for example positive ying & negative ying.

The fob of the key is a circle, depicting the divine. The tooth of the key is a square, depicting the physical world.

So each of us contains both the ying & yang, and have the ability to move on each of those two axes.

For each axis there are two polarities available to us as choices or potentials, one spiritual, one firmly rooted in earth. We have to balance both axes, be present in earth but also connected to the above, and this is the core symbolism of the cross -

- the center of the cross is where it's really at ! Bring your self into balance on both axes, male and female and you find the center point, the "fifth element" as it were... this is the ancient gnostic meaning of the phrase "being crucified on the cross".

simple really :-)