Best practices for protecting your SIM

Speeduser7533

What are current best practices for protecting your SIM card/number against attacks?

K8y

Speeduser7533 I was told here that there's no important info saved on SIMs, so out of curiosity what are you trying to protect against?

zzz

Speeduser7533

The only thing I'm aware of is some SIM-swap attack hardening:

https://en.m.wikipedia.org/wiki/SIM_swap_scam

https://www.vice.com/en/article/how-to-protect-yourself-from-sim-swapping-hacks/

Log on to your carrier's web portal, go into account settings, and enable any SIM-related security options you find there.
Avoid using your phone # to authenticate accounts wherever possible, but many services do not allow for this.
You can also try setting up a SIM pin:
https://www.androidpolice.com/enable-sim-lock-android-phone-protection/

Unfortunately though, its a losing battle.
Short of total divestment, the best you can hope for is some small harm reduction.
Mobile operator infrastructure (SS7) is deeply insecure.

For example:

https://www.vice.com/en/article/hacker-got-my-texts-16-dollars-sakari-netnumber/

https://www.404media.co/dhs-says-china-russia-iran-and-israel-are-spying-on-people-in-us-with-ss7/

And on the GOS site:

GrapheneOS always considers networks to be hostile and avoids placing trust in them. [...]

Cellular networks use inherently insecure protocols and have many trusted parties. Even if interception of the connection or some other man-in-the-middle attack along the network is not currently occurring, the network is still untrustworthy and information should not be sent unencrypted.

https://grapheneos.org/faq#cellular-tracking

Eagle_Owl

Speeduser7533
Hi Speeduser7533,
to protect your SIM card/number against SIM-swap attacks, read the articles zzz has mentioned and maybe watch some of the YT videos of some security guys, if you prefer watching over reading long articles. ;-)

There is nothing to add, but if they don't mention it enough, I can add one hint, not practical for everyone:
Don't give away your phone number to everyone! If you have more than one phone + number, then use one number to give away if absolutely necessary (doctor, business, delivery services, friends etc.).

But keep the other phone number secret. This number you give maybe your wife/husband and very very best friend (but only, if they never use evil services like Facebook, Insta or WA)!

Keep in mind: evil services create a shadow profile about you, even if you are not using their services!
And if one of your friends store your data in their address book, then you're screwed!
Because these evil services read the entire address book (not just phone numbers!!!)...

Speeduser7533

Someone trying to steal my number/account as one example (impersonating me).

I'm sure there are other risks.

K8y

zzz great advice: encrypt/lock your sim chip as link shows.

raccoondad

Keep in contact with your cell provider, tell them ASAP if your SIM card is stolen