HISTORY OF SIM CARD.

The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient, who sold the first 300 SIM cards to Finnish wireless network operator Radiolinja.

 The specification that standardized the micro-SIM form factor continues to evolve. Some features introduced recently include:

§  A micro-SIM form factor

§  Allowance for multiple simultaneous applications accessing the card through logical channels

§  Mutual authentication as a way to eliminate carrier spoofing by allowing the SIM card to authenticate the cell tower to which it is connecting

§  PIN protection with hierarchical PIN management with a universal PIN, an application PIN and a local PIN.

§     Expanded phone book storage on the SIM card with entries for email, second name, and groups.

subscriber identification module (SIM)

A subscriber identity module or subscriber identification module (SIM) is an integrated circuit that securely stores the service-subscriber key (IMSI) used to identify a subscriber on mobile telephony devices (such as mobile phones and computers).

 A SIM is held on a removable SIM card, which can be transferred between different mobile devices. SIM cards were first made the same size as a credit card (85.60 mm × 53.98 mm × 0.76 mm). The development of physically smaller mobile devices prompted the development of a smaller SIM card, the mini-SIM card. Mini-SIM cards have the same thickness as full-size cards, but their length and width are reduced to 25 mm × 15 mm.

 A SIM card contains its unique serial number (ICCID), internationally unique number of the mobile user (IMSI), security authentication and ciphering information, temporary information related to the local network, a list of the services the user has access to and two passwords (PIN for usual use and PUK for PIN unlocking).