One of the main Theft-Resistant lock are Key Control Locks:
This lock’s keys are not an easy key to copy compering to other regular lock’s key that can be copied in almost any hardware store like Home Depot, Ace and more.. Key controlled locks can be copied by the Company that installed them, usually a Locksmith company that makes keys* and in almost all cases they required to obtain a license to sell this type of locks after the manufacturers check the companies are in good stand.
Another way to be Safe From Burglars* are Saw Resistant Bolts:
You can find them in some deadbolts, they have special pins located inside they are made to prevent sawing the lock, every time you try to use a saw to cut through the lock the pins inside spin back and forth each time the saw’s blade hits the lock.
Comment ones are Anti-Drill Locks:
In this lock they put hardened pins in the front of the lock ahead of the key way where the pins of the lock are to prevent from drilling, as soon as the drill hits the lock in this area it stops and won’t go forward. usually you can find them in Hi-Security locks like Marks Hi-Security*.
Most Locksmiths and insurance companies recommend ANSI(American National Standards Institute)* Grade1 Deadbolts on exterior doors or entryways, on garage entrance doors as well. You can find different types of Grade1 locks that will all follow the same ‘American National Standards Institute’ standards. However, the will not provide the same protection as the others, what is mean is, that Grade1 deadbolts will give you a higher level of protection then a Grade1 privacy, both can be under Grade1 on the ANSI. That is why it is important to advice a Locksmith or you home insurance provider about your protection and the level of security you want to have in your property, whether it is your Home or Business. A Professional Local Locksmith can meet you at the property and even give you a few examples and show you the differences of the locks and level of security each provides.
ANSI(American National Standards Institute): https://en.wikipedia.org/wiki/ANSI_(disambiguation)
Locksmith company that makes keys: http://b1locksmith.com/where-to-have-keys-made-the-right-way
Marks Hi-Security Locks: http://b1locksmith.com/new-product-marks-hi-security-locks-superior-protection