The idea is just plain stupid:
Safety catches do not always prevent firearm accidents and even newfangled biometric guns, which check the identity of a user by their fingerprint, cannot stop thieves from using stolen ammunition in other weapons.
The way to make firearms really safe, says Hebert Meyerle of Germany, is to password-protect the ammunition itself.
Meyerle is patenting a design for a modified cartridge that would be fired by a burst of high-frequency radio energy. But the energy would only ignite the charge if a solid-state switch within the cartridge had been activated. This would only happen if a password entered into the gun using a tiny keypad matched one stored in the cartridge.
The people in the comments get it right. The commenters missed (as of my last reading) another concern of mine that the communication between the gun and the ammo might also be electronically jammed.
An idea doesn’t have to have a market to patentable and a patent was granted on this bad idea.