Car wont start because anti theft system. How to start?

I forget what its exactly call I know we had similar problem and after husband asked same ? On you tube he figured it out pretty quick sorry not real answer but hope it helps

Check all your battery cables negative runs from the battery terminal to both the fender wall and the transmission, positives mainly the one that runs from the battery to the main fuse and relay box directly attached to the core support at the front of the engine compartment under the hood. The other positive runs to the starter I would check these first. I spent too much money replacing parts I didn't need and found the problem to be one of the two positive cable.