SIM
termISP & telecomsecurity
Stands for: Subscriber Identity Module
The module holding a subscriber's identity and the key that authenticates them to a mobile network.
It is a hardware credential, and treating it as one explains both its strength and its most exploited weakness. The key never leaves the card, which is genuinely strong. The account behind it, however, is transferable by a support agent - which is what SIM swapping attacks, and why anything that treats possession of a phone number as proof of identity inherits the security of a call centre rather than of cryptography.
Also known as: Subscriber Identity Module, esim