Two calling cards are related, can I see my own things from other people's mobile phones?

The association of calling cards is shown as mother card or love card, and the communication between the two cards has preferential policies, such as free calls and short messages, which are not related to each other. Calling cards are only used to receive or transmit information. Personal information in the mobile phone is stored in the memory of the mobile phone, and the calling card can't get the data in the memory.

SIM card is called "subscriber identification card", which is actually a smart card with large-scale integrated circuit, and is used to register important data and information of users. One of the most important functions of SIM card is authentication and encryption. When a user moves to a new area to make or receive a call, the switch must authenticate the user to determine whether it is a legitimate user. At this time, both SIM card and switch use authentication algorithm to calculate authentication key and 8-bit random number. If the calculation results are the same, the SIM card is identified, otherwise the SIM card is rejected and the user cannot make a call. SIM card can also use encryption algorithm to encrypt voice to prevent eavesdropping.