or perhaps ward locks where the keys look like the keys from very old
locks such as:
when I was in sheriff joes jail they used ward locks.
if you know what your doing pin tunblem locks are fairly easy to open.
if you dont know what your doing cheep or old worn pin tumbler locks are also easy
to open. But if you don't know what your doing, or not very skilled
high quality pin tumbler locks are hard to open by raking.
ward locks are also easy to open. but to make a pick for a ward lock
its much harder then making a pick for a pin tumbler lock. I suspect thats
why they have ward locks in prisons & jails. because the inmates
dont have access to the tools to make the picks.
but if you have the tools picks or even keys are easy to make for
ward locks. for that matter if you have a blank key, a file,
pliers, and some wax or dye or smoke you can make a key to a
pin tumbler lock.
Its looks like magic but its based on sound physics.
the technique is called "impressioning". look it up on the
internet when you get out.