There's been a bit of chatter lately about the new "smart guns", guns equipped with grips that feel your grip as to determine who is holding the gun. Only if the authorized user is holding the gun, is it supposed to be able to fire. I'd like to theorize a bit about the pitfalls of this ideology.
No, I'm not going to make the "lend it out", "change your grip" or "criminals would rip the safety out" arguments over again. I'd like to focus on the "information" aspect.
The following text is strictly speculation, based on no evidence whats however, I am merely fantasizing, bear with me or tune out.
From pictures, I venture to guess that these grips have pressure sensors in them at various places. The lock and key model applies to this perfectly. Just like a key needs to be of specific height at every pin, I guess that your grip would have to be of sufficient strength but not too strong at each sensor. Just like locks allow for small deviation in key tooth height, a gun locking system would have to allow for some slight deviation as well.
This deviation, let's call it "tolerance" will be a factor of great interest; too loose and the lock will open for every grip. Too tight and even an experienced shooter will not be able to operate his own firearm. Laws would have to be drafted to regulate this tolerance, if not, a gun grip producer could market grips with such tolerance that pretty anybody with the same grip technique and hand size could operate a locked firearm, even if it wasn't "registered" to him/her.
There's a bigger problem. This information would have to be stored in the locking device, and can therefor be tampered with. A chip burner would become a pretty wise investment for a black market gun dealer or straw purchaser. This is assuming that the information is stored on a chip. I suppose it could be a magnetic strip such as on the credit cards that get hijacked cloned and altered on a regular basis by fraudsters and identity thieves. Heck, it could be a flash memory chip for all I know, which would pose even less of a challenge.
This may sound like organized crime turf, but is it really? People who buy defensive guns want the most reliable ones. Your average gun owner just might decide to make his gun more reliable by loosening up the tolerances, defeating the purpose of making his gun childproof for one. Said gun would have a higher chance of unlocking for a criminal as well.