Man, programmers constantly crack the security on $10,000 software. You can rechip your X-Box. You can rechip your car. I've disabled home security systems with an Insulated Handheld Short Circuit Device (this product is sold under the trade name "Screwdriver" by many fine companies throughout the world). They've hacked the scrolling displays in the NYC subway system. I know people who've read SEPTA's mail.
If you think that geeks can't crack smartguns, you're mistaken. As was said above, three wires and a battery can disable first gen smartguns. Let's say they go with something a little smarter, it's still entirely defeatable.
It's likely to be so absolutely simple that it's not even funny: drop 1.5 volts across the solenoid that releases the firingpin block, and suddenly your pistol functions just like an "oldschool" Glock.
Oooh, here's a possibility: your gun has a wireless transceiver in it, GPS, and a unique ID. Each time you pull the trigger, the internal chips send out your current geoloc along with your unique ID and a "Request to Shoot" opcode. This is picked up by the National Firearms Discharge Authorization System.
Your geoloc and ID are checked to see that you're discharging the weapon in an authorized location. Of course, if you're not a CCL holder, any non-home location is unauthorized (with the exception of shooting ranges). Next, an instant background check is run on you. This will include all arrest warrants, charges, and detainments by the police on an up-to-the-second basis.
If you check out, the system sends out a "Request Authorized" opcode to the individual chip processor, and the weapon discharges. If not, it doesn't, since you're obviously using the weapon in the comission of a crime (the crime being discharge of a firearm in a non-authorized area (switched to "attempted" after the fact)).
Also keep in mind that upon discharging the weapon (and sending the "Weapon Discharged" opcode), the system will check the Jurisdiction Tree for your current location and file for any appropriate arrest warrants. For instance, if you're in a City of the First Class, it might send out a request for a warrant for discharging a firearm in the city limits. This will, of course, post to the instant background check system. In many cases, the warrant may be granted quickly enough by the judge's computer that any followup shots are not authorized, since firearms posession by a fugitive from justice is illegal.
They can do this, to this extent, with a million redundant systems and processors. They can change to whatever mechanical systems they want (caseless, electrically fired, etc.). They can encrypt everything with one-time pads. It doesn't matter.
Fifteen minutes after they start selling a smart gun, there'll be a website hosted in Korea that offers the modchip.
(Of course, they'll criminalize those modchips. Maybe geeks will finally get the mob job offers they so rightly deserve. I know I've always wanted to be the "robbery technology guy/hacker dude" Hollywood stereoptype.)
