GSM SIM Card

SIM Card Introduction 2.1 Structure and type SIM card is a smart card with a microprocessor and it consists of the following modules: --- CPU --- Program memory (ROM) --- Working memory (RAM) --- Data memory (EPROM or E2PROM) --- Serial communication module These five modules must be integrated into an Integrated Circuit (IC), otherwise their safety would be threatened. This is because the chip connections may become illegal access and misappropriation of SIM cards important clues. In practice, there are two different forms of SIM cards with the same functions: (A) Full-size SIM card (commonly known as big card), this form of SIM cards with the IC cards of the ISO 7816 Standard [ISO7816], similar to IC card. The card has since been shrunk to the standard size of 25mm × 15mm. (B) Embedded SIM card (commonly known as small card), the size of only 25 mm × 15 mm, is a semi-permanent packed to the cards in the mobile station equipment. Two cards have installed waterproof, wear-resistant, anti-static contact with high accuracy and reliability characteristics. 2.2 Cryptographic algorithm and secret key in SIM card The most sensitive information of SIM card is the cryptographic algorithm A3, A8, secret Ki, PIN, PUK and Kc. A3, A8 algorithm were written into the SIM card in the producing process, and most people could not read A3, A8 algorithm. HN code could be settled by the phone owners. PUK code is held by the operator. Kc was derived in the process of encryption from Ki. 5 PIN and PUK: --- PIN –Personal Identification Number --- 2 PINs exist (PIN 1 and PIN2) --- Limited attempts on PIN access --- PUK –PIN Unblocking Code --- Resetting PUK, resets PIN and the attempt counter --- Too many attempts on PUK blocks use permanently --- CPU --- Program memory (ROM) --- Working memory (RAM) --- Data memory (EPROM or E2PROM) --- Serial communication module These five modules must be integrated into an Integrated Circuit (IC), otherwise their safety would be threatened. This is because the chip connections may become illegal access and misappropriation of SIM cards important clues. In practice, there are two different forms of SIM cards with the same functions: (A) Full-size SIM card (commonly known as big card), this form of SIM cards with the IC cards of the ISO 7816 Standard [ISO7816], similar to IC card. The card has since been shrunk to the standard size of 25mm × 15mm. (B) Embedded SIM card (commonly known as small card), the size of only 25 mm × 15 mm, is a semi-permanent packed to the cards in the mobile station equipment. Two cards have installed waterproof, wear-resistant, anti-static contact with high accuracy and reliability characteristics. 2.2 Cryptographic algorithm and secret key in SIM card The most sensitive information of SIM card is the cryptographic algorithm A3, A8, secret Ki, PIN, PUK and Kc. A3, A8 algorithm were written into the SIM card in the producing process, and most people could not read A3, A8 algorithm. HN code could be settled by the phone owners. PUK code is held by the operator. Kc was derived in the process of encryption from Ki. 5 PIN and PUK: --- PIN –Personal Identification Number --- 2 PINs exist (PIN 1 and PIN2) --- Limited attempts on PIN access --- PUK –PIN Unblocking Code --- Resetting PUK, resets PIN and the attempt counter --- Too many attempts on PUK blocks use permanently The following tables describe the two Phases of SIM card in GSM: (1) Phase 1 GSM system parameters Table 2-1 system parameter data options in phase 1 Identifier Name Length 6FAD Administrative 3 6F38 Service Table 4 6F07 IMSI 9 6F7B Forbidden PLMN 12 6F7E TMSI LAI 11 6F20 Kc, n 9 6F30 PLMN Selector 24 6F74 BCCH Information 16 6F78 Access Control 2 Service 1: PIN Disabling Service 2: Abbreviated Dialling Numbers Service 4: Short Message Storage Service 6: Capability Configuration Parameters Service 7: PLMN Selector Telecommunication business parameters Table 2-2 Telecommunication business options in phase 1 Identifier Name Length 6F3A Abbreviated Dialling Numbers 50*22 6F3D Capability Config Parameters 1*14 6F3CShort Message Storage 5*176 6F39 Carging Counter 2 (2) Phase 2 8 GSM system parameters Table 2-3 system parameter data options in phase 2 Identifier Name Length 6F05 Language Preferernce 4 6F07 IMSI 9 6F20 Kc,n 9 6F30 PLMN Selector 42 6F31 HPLMN Search 1 6F38 Service Table 4 6F45 Cell Broad Message ID 8 6F74 BCCH Information 16 6F78 Access Control 2 6F7B Forbidden PLMN 12 6F7E TMSI LAI 11 6FAD Admin Data 3 6FAE Phase Ident 2 Service 9: MSISDN Service 10: Extension 1 file Service 12: SMS parameters Service 13: Last Number Dialled Service 14: cell Broadcasting Message Identifier file telecommunication business parameters Table 2-4 Telecommunication business options in phase 2 Identifier Name 6F3A Abbreviated Dialling 6F3C Short Message Storage 6F3D Capability Configuration 6F40 MSISDN 6F42 SMS Paramters 6F43 SMS Status 6F44 Last Number Dialled 6F4A Extension 1 file 9 Short Message Storage 5*176 6F39 Carging Counter 2 (2) Phase 2 8