Cell Phones IMSI

What's the question…?

I want to make sure I understand what the IMSI is?

"Unique 15-digit IMSI number to allow foreign mobile networks to identify subscribers from abroad."

You can get info from the IMSI using this online tool Here

It's formed by MCC + MNC + MSIN
(Mobile Country Code + Mobile Network Code + Mobile Station Identification Number)

Keeper,

Is it true that the IMSI number can identify who is the subscriber of that sim card?

HunterD
If the subscriber has registered their correct details then yes once the IMSI is presented to the mobile network operator, the operator can produce results from a Subscriber Check identifying the name and address of the subscriber.

If you are asking whether the IMSI number itself identifies the subscriber's name, then the answer is unlikely.

trewmte,

Thanks for the info…

the IMSI identifies in an unique way the subscriber identity module (SIM) afaik.

indirectly, since normally the relation between a SIM card and a subscriber is 11 you should be able to identify the subscriber phisical person using the SIM IMSI.

be aware that old SIM cards, (from 2002 and previews) are easly cloned using a general PIC/EEPROM card, since there was a vulnerability wich allows a user to extract the KI from the original SIM in a reasonable amount of time. (about 2 hours).

here where i live, you also need a special written authorization to ask a network operator for such sensitive data.

indirectly, since normally the relation between a SIM card and a subscriber is 11 you should be able to identify the subscriber phisical person using the SIM IMSI.

As an alternative observaton, using vague terminology of 'indirectly', 'normally' and 'should' one could argue the foundation to the above statement relies too heavily on an 'expectation' based upon 'assumptions' that are being used to draw a 'conclusion'. By way of illustration the above statement excludes these normal possibilities

- the physical human being using the SIM card is NOT one and the same as the subscriber to the account (this is a normal event)

- where the subscriber account details are no more than an account number given to a prepaying SIM card user, who has never registered their personal details (this is a normal event)

- false registration details have been given (this is a normal event)

etc, etc…

I am not a mathematician, so what is the percentage figure of reliability with respect to finding a handset with a SIM card inserted (mobile station) and stating with certain that

a) identifying the subscriber account holder's name and address?
b) that the subscriber account holder is the only user of the account?

If I may, you have to add that, even assuming that the subscriber data are correct, this data is ONLY available to the GSM network who issued the SIM, an d I doubt that without a Court Order the phone company will ever give the data away (unless you are the FBI, the NSA or both 😉 - or equivalent in your country)

Thus, there are two main factors that must be taken into account
1) the accuracy of the phone company database
2) the availability of this database

Whilst the first, depending on type of subscription, phone company and country where it was issued, may give from a statistical point a very high probability to find the "index" of the database entry, the latter, unless the exceptions given above apply, quickly bring down overall probability of finding a name and address to nice, round 0%.

Even if the data is available, in a number of countries you just enter a shop, give them a photocopy of an ID document - even that of another person - fill a form and buy a subscription.

Expecially if you give a photocopy of a document from another Country, possibly written in another language, which chances are there that the shop clerk can say it's a fake.

I am sure I could get easily a SIM to the name of

Mr. George Washington
1600 Pennsylvania Ave NW
Washington, DC 20500

without problems.

And of course there is no way in the world - except maybe an actual call recording and a voice comparison matching, to affirm that the subscriber actually made one particular call
he could have lost the phone
had the SIM cloned
had the phone stolen (even temporarily)
had it borrowed by a friend, relative, or even by a passer-by with some excuse

jaclaz