my truck wont start until I release the switch key. then it cranks.

What is your question?

when I turn the engine over in my truck it turns over fine. but will not crank. but when I release the key and the starter motor all but stops. it starts. it has always cranked fine. this problem just recently started. and sometimes a "security" light comes on in my instrument panel. I heard that the ignition switch could be bad and shutting my fuel pump off.