Where does this come from, and can I check it?

Subscriber Identity Modules securely hold mobile network identity keys on smart card chips. The figure is taken from GSMA Association, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Yes. It sits on the Technology shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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Mondo Knows Facts

The SIM card was invented in 1991 by Giesecke Devrient in Munich

Subscriber Identity Modules securely hold mobile network identity keys on smart card chips

German smart card manufacturer Giesecke & Devrient produced the first commercial Subscriber Identity Module (SIM) cards in 1991 for Finnish network operator Radiolinja. The SIM card stores international mobile subscriber identity (IMSI) numbers and cryptographic authentication keys. This allowed subscribers to switch mobile handsets easily while preserving their network identity.

Where this comes from

GSMA Association

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Tags: sim-card, telecoms, mobile

The SIM card was invented in 1991 by Giesecke Devrient in Munich: the short answers

Where does this come from, and can I check it?: Subscriber Identity Modules securely hold mobile network identity keys on smart card chips. The figure is taken from GSMA Association, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a technology fact?: Yes. It sits on the Technology shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.