Most cables can be snipped through in 10-15 seconds. Most U-locks and security chains can be defeated by an angle grinder in 10-15 seconds. Aluminum shell locks like the SAF Altor will resist most thieves; however it weighs as much as some bikes and costs a bundle. As you improve lock security, there are many other things that become weak links. For example, a lot of bike racks are not bolted to the ground, or if they are, it's with simple hex nuts that can be unscrewed easily. Many bike racks are rather flimsy so the thief can easily cut or break them.
Bike security garages are the way to go. Yes the locks can be defeated, but the thief will avoid just because he or she won't be able to see the contents.
The best anti-theft bike is a rusty ugly one with bad tires parked next to a nice newish one. Many riders try to uglify their bikes for this reason.
Good luck on your project