International Mobile Subscriber Identity (Reference: MM, GSM, mobile-systems)
IMSI-catcher
TELEPHONY EAVESDROPPING DEVICE
IMSI catcher; I.M.S.I. catcher; I. M. S. I. catcher; I M S I catcher
An international mobile subscriber identity-catcher, or IMSI-catcher, is a telephone eavesdropping device used for intercepting mobile phone traffic and tracking location data of mobile phone users. Essentially a "fake" mobile tower acting between the target mobile phone and the service provider's real towers, it is considered a man-in-the-middle (MITM) attack.
A NUMBER THAT UNIQUELY IDENTIFIES EVERY USER OF A CELLULAR NETWORK
E.212; International Mobile Subscriber Identities; International Mobile Subscriber Identity
The international mobile subscriber identity (IMSI) is a number that uniquely identifies every user of a cellular network. It is stored as a field and is sent by the mobile device to the network.