Unauthorised Access: Physical Penetration Testing For IT Security Teams

5.3. Advanced Techniques

Having covered the basic traditional methods of opening a pin tumbler lock, you may be relieved or (possibly annoyed) to know that there are easier ways. These methods are universally eschewed by lock picking purists but then they're not the ones who may need to open locks under pressure at night, in the rain.

5.3.1. Using the Snap Gun

The snap gun is an automatic lock tool that makes the process of opening pin tumbler locks considerably easier. The device was initially developed for law enforcement officers who had no training in lock picking and who needed to open doors quickly – or so the story goes.

The process of opening a lock with a snap gun is simple but a little different than using a pick and torque wrench. With a snap gun, a torque wrench still needs to be used except you don't try and set one pin at a time. Each time the trigger on the snap gun is pulled the needle is drawn up and strikes all the key pins simultaneously. This action (via transfer of energy) causes all the driver pins to be thrown upwards. This results in a gap at the sheer line. So in practice:

1. Insert the snap gun needle into lock parallel with pins.

2. Pull the trigger five times quickly while keeping constant pressure on the torque wrench.

   Figure 5.17. The Snap Gun.

   

3. If the lock fails to open, increase the strength of the striking motion on the snap gun and repeat.

Most locks ...