Re:Did 5G Kill the IMSI Catcher?
by toast0 on Sunday April 27, 2025 @02:47PM
(#43814193)
There's a convenient toggle on my Moto G Stylus 5G 2023, if not a convenient name. In the carrier settings right next to allow 5G. Can't easily disable 3G or LTE though. IIRC, LTE is also mutually authenticates, but if we're talking about passive catching and the ismi is sent in the clear as the article says, then that doesn't eliminate passive catching. I'm not sure about 3G, I thought it wasn't mutual auth either.
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Definitely, mutual authentication and (not) using long-term identifiers in the initial attach request are largely orthogonal concerns.
I believe even 3G supports mutual authentication (at least if the SIM supports it, i.e. it’s not a very old GSM only one), but anonymized identifiers only appeared with 5G.
wait. which market? never seen a Motorola with the "disable 2G" toggle!
and yes, that only prevents the lower denominator which uses downgrade, which is the vast majority everywhere.