How to block satellite signals

Hi! Hypothetically speaking, in a mobile operating environment while traveling the highway at 70 MPH with thousands of other vehicles, it would be the proverbial search for a needle in a hay pallet. This would be especially true for a GPS-only locking device, which would require very low power to block weak satellite signals. It presents an interesting problem for the secure execution office in cash. As for jamming the signal of those GPS L-bands, they can't be cell phone jammer all at once. The main reason of this is because three of GPS bands are for civil usage and two for military usage. All civil GPS bands jamming device will easily block three civil GPS frequency bands, but military ones are forbidden to be jammed and they are protected well.