Safer gun technologies

Contents:

  • Table 1: Enabling Technology for Fingerprint-Activated “Smart” Guns
  • Table 2: Electronic Gun Safety Technology
  • Table 3: Mechanical Gun Safety Technology

Table 1: Enabling Technology for Fingerprint-Activated “Smart” Guns

IMPORTANT NOTE: The inclusion of information in this table about a specific device does NOT mean that the device is available for use in a gun. Due to product liability concerns, no semiconductor company allows the use of its products in ANY health- or safety-related application — such as a gun — without the explicit written consent from the company’s senior management or Board of Directors.

Technologies Required to Make a Fingerprint SystemHow it worksSupplier(s) and Status
Fingerprint image sensorThere are two main types of fingerprint sensors – optical sensors and “chip” sensors. Optical sensors uses a lens and are much too big for use in a gun but generally give better images than chip sensors, are not affected by static and have a faster readout and larger scan area.Note: Special techniques must be used to obtain a fingerprint image from a live finger. A simple photograph does not work because the contrast between ridges and valleys is much too low to produce a good image.User places his/her fingertip upon the sensor so that an image of the tiny but distinctive ridges and valleys of the fingerprint can be captured and processed by an external image processor.The larger the area of the finger that is sensed, the more ridges and valleys are captured and the more distinctive the fingerprint is.The sensor itself cannot capture, process or verify images because it has no memory or processing capability. It is like a camera without film.At 500 dots per inch, a common resolution for the capture of fingerprints, it is common to have 64,000 or more, 8-bit picture elements or “pixels” to process.The amount of time to capture an image, the size of the sensor and thus the extent of the captured image and uniqueness of the fingerprint, the cost, the resistance of the sensor to damage, and the ability of the sensor to operate in different environments, all vary depending upon the sensor technology.Infineon “FingerTip Sensor” – Semiconductor “capacitive” sensor is about 15 x 20 mm, housed in a package about 30 mm square, sensitive to static discharge. At least 1/10 second is required to obtain a single image, and it is usually necessary to capture several, at 1/10 second each, depending upon the details of how an external processor knows when to capture an image. Approx. $25 in large volume. Available. A German company formerly known as Siemens Semiconductor. This sensor is reportedly being using in the external fingerprint module being used with the S&W “smart” gun prototype. It is evidently being used in an external module due to its large size. We do not know if Infineon has approved its use in or with a gun.
Image processorA processor operates under software control and receives raw image data from the fingerprint image sensor.Depending upon the software used, it: (1) completes the formation of a fingerprint image, (2) determines whether or not additional fingerprint images are required so as to have a quality image, (3) processes/enhances the image in preparation for extracting distinctive information from it, (4) extracts distinctive information from it, (5) compares that information to information about the fingerprints that are authorized to fire the gun, and (6) sends a signal to the mechanism that enables the gun to fire if the user is authorized to fire the gun.The entire task must be done extremely quickly, in less than about 1/10 of a second, if a “smart” gun is to be used normally, in the same way as an ordinary gun.General purpose digital signal processor (DSP) chips are made by Analog DevicesMotorola, Texas Instruments and others. These processors manipulate fingerprint images much too slowly for use in a gun since they generally only handle one picture element at a time, and many picture elements must be processed very quickly.
Fingerprint software for autonomous applications (operate without a PC)The rapid processing of fingerprints is fundamentally difficult because a large number of data points or picture elements must be processed, the images are complex and often corrupted, and there are many variables that affect the appearance of the print.It is relatively easy to make a standalone or autonomous (as opposed to FBI) fingerprint system work in the lab, but difficult to make it work reliably in practical applications.However, these problems can be overcome given proper sensors, sufficient processing power and sophisticated algorithms.A key variable in a practical fingerprint system is the location and orientation of a fingertip upon a fingerprint sensor. Most fingerprint sensors are built into a housing that tries to force the user to place his/her fingertip on the sensor in a particular way to minimize the number of variables that the fingerprint software, which processes the images, has to handle.In addition, the fingerprint system must deal with changes in a given fingerprint, such as from moisture, cuts, cracks, dirt and grease. These changes can obscure portions of the fingerprint, expand or contract the fingerprint, or create false details.Most fingerprint software extracts distinctive details called “minutia points” from the pattern of ridges in a fingerprint. Typical minutia points are the joining of two ridge lines, or the splitting or termination of a ridge line. When a live fingerprint is taken by the police, who generally capture the largest possible print, 40 or more minutia points are usually obtained from a single fingertip.The use of fingerprints for identification is considered highly reliable worldwide, and is widely and routinely used by the FBI.Most fingerprint software has been developed under the assumption that the amount of computer power available is quite limited.Mytec recently announced that they have developed a fingerprint module using an Infineon fingerprint sensor (see above) and their fingerprint software for use external to a prototype “smart” gun being developed by Smith & Wesson (see below). Several newspaper articles about their development seemed to credit Mytec for development of the sensor which is, in fact, made by Infineon. Other than saying that the fingerprint module is so large that it cannot be built into the handle of a gun, no performance specifications for the speed, accuracy or number of users of the fingerprint system were provided.

Table 2: Electronic Gun Safety Technology

Electronic TechnologyHow it would workSupplier(s) and StatusWorks withPrice US$
Fingerprint in handleHow it would work.Technical overview.Progress.Authorized user would pick up a gun, aim and fire, like with an ordinary gun, and with the same speed. One or more of the user’s fingertips would automatically land upon a specially designed fingerprint sensor that provides the high speed, ease-of-use and resistance to static required. The total time to activate the gun would be less than 2/10 second. One or more persons could use the same gun.User’s fingerprint would be quickly and automatically captured and verified within the handle of the gun so only authorized user(s) could fire the gun. Operation would be as foolproof as possible. Once enabled to fire, the gun could be fired until the owner lets go of it or runs out of ammunition. Each time the gun is picked up, a self-test circuit would verify the proper operation of the gun and confirm that sufficient battery power is available.Could only be built into new guns, but could also be built into new trigger locks, magazines, lock boxes and safes.Add $100 (est.) to retail price of gun.
Fingerprint in external moduleRef: The Wall Street Journal, Jan. 27, 2000, page B1, “Smart Guns Trigger a Debate”: In a prototype, the user places a special fingerprint module about the size of the gun handle into the butt of a specially built gun. He then scans his fingerprint into the module. Once the user is authorized, the module is removed and the ammunition magazine can be inserted into the gun handle. Grip sensors detect that the user has a firm grasp to activate the weapon. A new type of electrically-fired ammunition is used.Comments: A problematic human interface is used. It requires a lengthy several-step process that requires two hands and a large removable fingerprint module to be able to use the gun.It is not clear: (1) how long it takes for a fingerprint to be processed, (2) how accurate, reliable and easy to use the fingerprint module is, (3) how many different fingerprints/users can be used, (4) how long the gun remains active once armed, (5) how a fingerprint is entered into the module, (6) how the gun becomes disarmed, (7) whether or not the operation of the module can be circumvented, (8) whether or not a gun can be stolen and used with another module, (9) how reliable the new ammunition and firing mechanism are, (10) how many shots can be fired on a set of batteries, (11) how one knows how much power is available to operate the gun and module, (12) what the requirements are for storage of the module, or (13) why a new and unproven type of ammunition, which is fired electrically, is used.Smith & Wesson Corp., Springfield, MA, tel. 800-331-0852, 100+ year-old gun company.Status: Prototype but not publicly demonstrated.Company is reportedly looking for Federal funding and has hired Washington lobbyists to try to get it. Incongrously, company has stated that personalized guns have a large market but it may drop the project if it cannot get government funding for it.According to a press release, module uses a “FingerTip” fingerprint sensor made by Infineon, a German semiconductor company.Comments:The construction and large size of this sensor appear to make it difficult to eliminate the separate fingerprint module and put the sensor into the handle of the gun. Furthermore, if the size of the sensor were reduced, the size of the fingerprint image would be reduced and it would be much more difficult if not impossible to distinguish one user from another.In addition, the primary innovation is apparently not the fingerprint technology but the use of an electronic firing mechanism instead of a conventional mechanical firing mechanism. As we understand it, the use of this electronic mechanism means that no firing pin strikes the bullet, removing a means for identifying which gun fired the bullet. This is contrary to the $65 million that the govt. is investing in technology to identify which gun fires a particular bullet used in a crime.Could only be built into new guns.Add $300 (est.) to retail price of gun.Reportedly at least two years from market.
Radio frequency in handle and wristbandGun user wears a wrist band containing a small radio transmitter. The transmitter sends a signal to a receiver in the handle of the gun to activate it.Colt Manufacturing Co., West Hartford, CT, tel. 860-244-1428Status: Abandoned. Colt has stopped manufacturing consumer products and split off a new company, iColt, to work on smart guns, but iColt has since closed.Could only be built into new guns.Not applicable
Combination lock in barrelGun user enters a combination into a series of pushbuttons beneath the barrel of a gun. Company says these guns are not really “smart” guns.SIG Arms Inc., Exeter, NH, tel. 603-772-2302Status: Production summer of 2000. Company is reportedly for sale.Could only be built into new guns.Guns cost $950.

Table 3: Mechanical Gun Safety Technology

Mechanical TechnologyHow it worksSupplier(s)Works with Price US$
Barrel block, cableCable with locking mechanism extends down barrel of gun, preventing it from being firedTrigger lock from Hodge Products, El Cajon, CA, tel. 800 778-2217Any gun$10 up
Trigger block, mechanicalBlock fits between back of trigger and trigger guard and is secured by padlockSaf-T-Block from Concept Development, Scottsdale, AZ, tel. 800 472-4405Any gun$20
Barrel block, rodMetal rod with locking mechanism extends down barrel of gun, preventing bullets from entering firing chamberChamber-Safe from Rocky Mountain Tool & Armory, Huntington Beach, CA, tel: 714 848-3234.Selected guns$30
Trigger block, magnetic, integratedInternal pin blocks trigger mechanism, and is released when user wears a magnetic ringMagloc from Smart Lock Technology, Richmond, BC, tel. 604 551-8492Selected guns$70
Trigger lock, detachedClamshell device fits over trigger mechanism, immobilizing it. Requires key or combination to open. In mechanical and electromechanical styles.Master Lock Co., Milwaukee, WI, tel. 414 444-2800; Speed Release, Dallas, TX, tel. 800 939-2311; Hodge Products, El Cajon, CA tel. 800 778-2217Any gun$10 up
Trigger lock, built-inSmall hex key with hollow end turns shaft in rear of gun handle to lock/unlock triggerTaurus Firearms, Miami, FL, tel. 800-327-3776Selected gun modelsvaries
Trigger lock, integratedCombination lock in gun grips prevents trigger from being pulledSaf-T-Lok, West Palm Beach, FL, tel. 561-478-5625Selected gun models$70
Hammer lock, mechanicalDevice prevents firing pin from coming in contact with bullet. Can sound alarm.Gunlock, Inc., North Haven, CT, tel. 203 239-5958Any gun$35
Removable hammerHammer can be removed then reinstalled quickly when gun is neededSaf-T-Hammer Corporation, Scottsdale, AZ, tel. 877 723-8426Many guns$50
Hammer lock, magneticMagnet in revolver frame prevents hammer from moving unless user is wearing a magnetic ringMagna-Trigger from Tarnhelm Supply Co., Boscawen, NH, tel. 603 796-2551Selected S&W gun models$250 plus $40 for a ring
Hammer lock, magneticMagnet in shotgun frame prevents hammer from moving unless user is wearing a magnetic ringShotguns from Mossberg, North Haven, CT, tel. 203-230-5380Selected modelsvaries
Hammer lock, magneticFulton Arms, Houston, says it will have a smart gun on the market in a matter of weeks that unlocks by reading a magnetic code, similar to the magnetic strip found on the back of a credit card. [Philadelphia Inquirer, June 1998]Fulton Arms, Houston, TX, claims to be inventor of term “smart gun”
Magazine lockCombination lock in pistol grip prevents bullets from entering firing chamberSaf-T-Lok, West Palm Beach, FL, tel. 561 478-5625Selected gun models$90
Chamber indicatorsVisual indication of whether or not a bullet is in the chamberWalther, BerettaSelected modelsvaries

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