05. SIM card issues

sim card = a chip :
1. data store (do not store contacts on SIM)
2. programmable logic on chip
main purpose : ==identify carier & billable identty / person==
it does this with an IMSI number , stored on the sim
also phone number wordt opgeslagen op SIM card
standaard IMSI is normally not transferred to the network, instead TMSI (= a temp, calculated IMSI) is used (can be hacked)

TMSI handshake 2 network => network challege to phone => phone calculates Ki + random value = response => network checks / verifie

a phone is configure to only talk to cariers as configured on the sim card
so it will on connect to the trasmiter/receiver towers from that carrier
exception :
- emergency calls
- roaming in buitenland

Providers have databases with permanent subscriber information known as HLR (Home Location Register)

IMSI is used to find people on the network (to be called bv.)
IMSI + Ki = you can create a duplicate sim card

encrypted traffic

4G : encrypted must be enabled
3G : encrypted can be disabled
if downgrade to 3G is allowed , then encryption can be disabled
this is not done by the carrier network, but the phone will respond to the commands , f.i from gov agency that sents network signals or hackers
=> hacking # 1 = IMSI catcher ( stingray)
phone by design tries to connect to the strongest cell tower ==> hacker makes sure his signal is exctremely strong
lesser distance = stronger signal

NO SIM card present

when there is no SIM card connected,
the phone will use the IMEI number to connect to the emergency services such as 911 or 112.
{wm : only at phone request , or is it always broadcasted , like with SIM handshakes }
international emergency nr are configured to be allowed to be dialed without a sim card present in a phone.
your phone will the send signal to nearest tower independent of service provide and will dial using that network.
These no’s can also be dialed from locked screen without entering lock code.

it still can be used with wifi , therfore tracking using IP and/or MAC
it still can be tracked using GPS

Doc

o.m. :
Phone SIM Card Use Privacy Strategies – https://www.youtube.com/watch?v=k6_fB_phgY8