What do you consider a "high security lock"?
Abloy :-)
More seriously, a high secruity lock will have hardened stteel parts so
it can't be sawn or drilled (easily). It will be dififcult to pick,
either due to the design (the Abloy sidebar mechansim) or anti-picking
fetures. In the case of a padlock, there will be limited spare cound the
chackle so you can't get a crowbar in.
Any lock can be picked, any material can be cut or ground through. THe
idea is to make 'chummy' desicde that some other building is an easier
target :-)
-tony