4 ms·
How come the tower doesn't have to cryptographically authenticate with the phone? Like websites do, using TLS certificates.
by H8crilA 3y ago
How come the tower doesn't have to cryptographically authenticate with the phone? Like websites do, using TLS certificates.
- Ms-J 3y agoThis may be of use to you: https://blog.cryptographyengineering.com/2013/05/14/a-few-thoughts-on-cellular-encryption/ https://blog.cryptographyengineering.com/2013/05/14/a-few-th... "GSM phones authenticate to the tower, but the tower doesn’t authenticate back. This means that anyone can create a ‘fake’ tower that your phone will connect to. The major problem here is that in GSM, the tower gets to pick the encryption algorithm! That means your attacker can simply turn encryption off (by setting encryption ‘algorithm’ A5/0) and simply route the cleartext data itself.In theory your phone is supposed to alert you to this kind of attack, but the SIM chip contains a bit that can de-active the warning. And (as researcher Chris Paget discovered) carriers often set this bit."
- livueta 3y agoAlong with the sibling comment, there are also protocol downgrade attacks analogous to what HSTS prevents in HTTP/S. IIRC these require active jamming, but if you're .gov who cares. This is a reason why security-conscious OSes like Graphene allow explicitly disabling older protocols.
- Ms-J 3y agoYou can also disable these in regular Android, depending on the phone manufacture. Look for your phone's engineering screens.