Thomas Kunz
Systems and Computer Engineering
39
GSM - Authentication
A3
RAND
Ki
128 bit
128 bit
SRES*  32 bit
A3
RAND
Ki
128 bit
128 bit
SRES    32 bit
SRES* =? SRES
SRES
RAND
SRES
32 bit
mobile network
SIM
AC
MSC
SIM
Ki: individual subscriber authentication key SRES: signed response