Biometrics can be classified according to the type of biometric data used, e.g., face, iris, voice, signature, or hand geometry identification. However, all these methods take the same authentication process.

RFID is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID tag). The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it.

An RFID system consists of a tag, which is made up of a microchip with an antenna, and an interrogator or reader with an antenna. The reader sends out electromagnetic waves. The tag antenna is tuned to receive these waves. A passive RFID tag draws power from field created by the reader and uses it to power the microchip's circuits. The chip then modulates the waves that the tag sends back to the reader and the reader converts the new waves into digital data.

The big difference between bar codes and RFID is that bar codes are line-of-sight technology. That is, a scanner has to "see" the bar code to read it, which means people usually have to orient the bar code towards a scanner for it to be read. Radio frequency identification, by contrast, doesn't require line of sight. RFID tags can be read as long as they are within range of a reader. Bar codes have other shortcomings as well. If a label is ripped, soiled or falls off, there is no way to scan the item. And standard bar codes identify only the manufacturer and product, not the unique item. The bar code on one milk carton is the same as every other, making it impossible to identify which one might pass its expiration date first.

Microchips in RFID tags can be read-write or read-only. With read-write chips, you can add information to the tag or write over existing information when the tag is within range of a reader, or interrogator. Read-write tags usually have a serial number that can't be written over. Additional blocks of data can be used to store additional information about the items the tag is attached to. Some read-only microchips have information stored on them during the manufacturing process. The information on such chips can never been changed. Other tags can have a serial number written to it once and then that information can't be overwritten later.

The process requires conversion of a bar code that can be printed on or affixed to an item, and subsequently read by a light source and fed into a computer.

When a bar code scanner is passed over the bar code:
The light source from the scanner is absorbed by the dark bars and reflected by the light spaces.
A photocell detector in the scanner receives the reflected light and converts the light in to an electrical signal.
As the barcode is scanned, a low electrical signal for the spaces (reflected light) and a high electrical signal for the bars are created. The duration of the electrical signal determines wide vs. narrow elements. This signal can be "decoded" by the bar code reader's decoder into the character that the bar code represents.
The decoded data is then passed to the computer in a traditional data format.

Bar Code scanners are faster than the human eye and far more accurate. Based on tests, bar code information has an accuracy rate of 1 error per 10,000,000 characters. Compare that to keyboard error rates of 1 error per 100 characters. This form of "automatic identification" can help prevent misidentification errors, which can help save lives and money.

GSM is an open, non-proprietary system that is constantly evolving. One of its great strengths is the international roaming capability. This gives consumers seamless and same standardized same number connectivity in almost all countries. GSM satellite roaming has extended service access to areas where terrestrial coverage is not available.

GSM differs from first generation wireless systems in that it uses digital technology and time division multiple access transmission methods. Voice is digitally encoded via a unique encoder, which emulates the characteristics of human speech. This method of transmission permits a very efficient data rate/information content ratio.

From the outset, GSM has been a system designed with stringent levels of inbuilt security. With constantly enhanced transmission protocols and algorithms added to the flexible and future proof platform, GSM remains the most secure public wireless standard in the world.

The GSM Association, based in Dublin, Ireland and London, UK, represents the interests of more than 690 GSM satellite and 3G operators, key manufacturers and suppliers to the GSM industry as well as regulatory and administrative bodies from more than 190 countries and regions around the world. Most of the first third generation licensees are also members. The GSM Association is responsible for the continued maintenance of open standards and interoperability. The global cooperation between operators is most powerfully illuminated by the success of international roaming. One of the Association's major priorities is the development and promotion of the GSM standard worldwide.