In everyday speech, the word "SIM" is a device that is an electronic identifier, which belongs to the more general class of "smart cards". Technically, a SIM card is a microprocessor embedded in a small piece of plastic. Each such "smart record" is assigned ICCID - a special code of the international format.
What information is contained on the SIM card
A SIM-card is a device made in the form of a piece of plastic with a “smart filling”. It is one of the subscriber identification modules in telephone networks (Subscriber Identification Module). It is a microcomputer, which includes a microprocessor and a set of memory types: permanent / operative / rewritable (ROM / RAM / EEPROM). Communication with the outside world takes place through an interface that consists of several electrical contacts.
SIM'ka has buses for input and output of information and stores various information (both open and protected). First of all, this is user information of a general nature: SIM-menu, phone book, call lists, short messages, as well as various additional options. Then - the user's personal identification numbers PIN and PUK, which are the secret codes of the SIM card. A four-digit PIN (Personal Identification Number) is recorded on the card upon issue. Together with it, the cardholder is informed of the PUK1 / PUK2 unblocking codes (PIN Unblocking Key). With their help, it is possible not only to unlock the phone, but also to change the PIN-code.
A necessary attribute of a SIM card is the identification data recorded on it. They are designated by the following abbreviations:
Ki (Key) - a unique key used to authenticate the SIM card in the GSM mobile network. This is the 128-bit value assigned to the SIM during the carrier personalization process.
IMSI is an identification number that a mobile subscriber uses when entering the international communication space (International Mobile Subscriber Identifier). In fact, this is the username on the system. This number allows you to link the cardholder to his account with the provider.
IMEI stands for International Mobile Equipment Identity. It is used in cell phones of GSM, WCDMA and IDEN networks, as well as in some satellite phones. The value is unique for each device used.
ICCID is an international SIM card code that identifies a subscriber with an operator providing communication services (Integrated Circuit Card ID). It is entered into the provider's database, and is also stored on the SIM in an unprotected form. In fact, this code is the unique serial number of each individual electronic identifier. When replacing the SIM card, you can save the phone number, you cannot leave the same SIM card number. The ICCID is specific to each physical medium.
ICCID encoding
The abbreviation ICCID refers directly to the SIM-card, literally means "identification code of the microcircuit" (Integrated Circuit Card ID). This is a block of 19 or 20 digits, which contains information about where and for whom the SIM card was issued (country, manufacturer, release date, operator), its individual internal number and the coding control value.
Since the numbers on SIM cards should not be repeated even by accident, the rules provided for by the international technical standard ITU-T E.118 are applied to generate ICCIDs.
- the first two digits are MII (Major Industry Identifier), an industry identifier according to the ISO / IEC 7812-1 standard. The main industry code used for telecommunications purposes is 89. That is, all SIM cards always have a serial number starting with 89.
- characters from the third to the fourth (or the fifth) - the telephone country code according to the recommendation E.164. This technical standard specifies the general international telecommunication numbering plan and the format of numbers used in telephone networks. For any region of the Russian Federation, the value is 7.
- the next four (or five) digits - identify the organization that issued the card. The numbers are indicated, which are issued by the international telecommunication units ITU-T to each telecom operator that issues SIM-cards. For example, for a Beeline subscriber in the federal network of GSM-900 standard, the encoding will be 01 99.
- 18th (or 19th) digits - internal SIM card identifier. The organization providing communication services defines this code not according to a general standard, but in accordance with its regulations. Thus, each physical piece of plastic is linked to the identifier of the software part at the provider.
- one character (last) - control ratio of the serial number (Parity). This is a number (sometimes a letter), which is calculated from all other ICCID numbers using a special Luna algorithm. The algorithm is simple and not cryptographic. "Control" testifies to the fact that during encoding in the international identifier "SIM" there was no inadvertent distortion of data.
The unique serial number of the SIM card is a set of numbers grouped into three ICCID miniblocks = (IE) + (IR) + (P).
Comments on decoding ICCID for example: 89 7 01 99 1111XXXX607 3
IE (IIN) - Issuer Identification Number. Taken together, the first three encoding fields (from the 1st to the 7th character in total): 89 - fixed digits for all SIM-cards; 7 - Russia; 01 - federal network of GSM-900 standard; 99 - communications operator "Beeline".
IR (IID) - SIM card identifier (Individual ID). A block of 11 subsequent digits (from 8th to 18th) is the internal number encoded by the telecom operator. In this case: 1111XXXX607 in Beeline format.
P (P) - control ratio in coding digits (Parity). The last character in a sequence of 19 or 20 characters. In the given example: 3.
In practice, on GSM SIM cards, depending on the manufacturer, ICCIDs are used both 19-bit (18 code digits + 1 control ratio) and 20-bit (19 coding digits + 1 control value). However, each issuer always uses the same code size for its ICCIDs.
How to find out the ICCID of a SIM card
The unique serial number of the SIM card is stored on it in an unprotected form, it can be easily read in several ways.
- The simplest thing is to look at the serial number of the device on the box with the SIM card. IPad has ICCID engraved on the back cover.
- Most often, the identifier is stuffed directly on the SIM card: on its back side, near the chip. ICCID numbers are laser engraved onto the plastic part of the physical medium.
- Information can be found directly in the "mobile phone" when the card is installed in it. Owners of Apple appliances need to go to "Settings", select "General", then click "About device". For smartphones running on Android OS, it is enough to perform similar actions: menu item "About phone", then "General information" and "SIM-cards". If you have an unactivated iPhone, the procedure is as follows. The device should be locked. Upon further unlocking, the I symbol will appear on the screen (bottom right). When you click on this "icon", the information of interest will appear.
- Experts position this method of obtaining information about the SIM card as the simplest and most accurate. We connect the iPad to the computer via a wire. Go to iTunes and select your iPad. Information will appear in the main window. We look at the line "serial number".
- It is possible to find out the unique number of the SIM card by installing alternative software. You can download programs such as SIM Serial Number or SIM Card Details. For Android devices, it is recommended to use a special application of the same name ICCID.
