Subscriber Identity Module (SIM) is part of a smart card ICC (Integrated Circuit Card), also known as SIM Cards, for mobile, telephony devices (such as computers) and mobile phones. SIM cards securely store the service-subscriber key (IMSI) used to identify a subscriber, plus a set of subscriber-specific and service provider-specific information. Most SIM cards are removable, and can allow a user to move a subscription from one device to another by moving the SIM. However, we expect to see new SIM form factors, based on non-removable chips, specifically for M2M in the near future.