SIM lock


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SIM lock

(Subscriber Identity Module lock) A function in GSM cellphones that restricts the phone's use to a particular cellular carrier (a particular SIM card). SIM locks are used to ensure subscribers finish their service contracts when the phones are heavily subsidized by the carrier. SIM locked phones may be unlocked by entering a code.

Apple's iPhone brought the SIM lock into public view because of its original exclusivity in the U.S. with AT&T. However, iPhones were readily "unlocked" by hackers both in and outside the U.S., not only to use a different carrier, but to customize their appearance and download applications even before Apple debuted its App Store. In addition, Apple allowed the GSM iPhone to be sold without the SIM lock in Australia, Taiwan, Hong Kong and other regions where locked phones were either prohibited or a recipe for marketing failure. See SIM card and iPhone jailbreaking.
References in periodicals archive ?
Robust hardware security blocks for implementing SIM lock, flash lock
For enterprises, Vodafone offers the capability to disable micro SD card functionality, as also the capability to lock SIM card to a specific dongle through a SIM lock / unlock tool.
announced today that customers may request to have the SIM lock capability removed in principle from any DOCOMO wireless device newly marketed on or after April 1, 2011.