3 ms·

Even 4G (LTE) is typically end to end encrypted. Unsure what you are trying to say or if you're just trolling.

pjc50 10y ago
Isn't it just mobile station to base station encryption, not true E2E encryption of calls (which would never be allowed)?
- kristoffer 10y ago
  No the core network uses IPSec. Of course there is support for "lawful interception" though.
  - kristoffer 10y ago
    Or rather has support for IPSec, not all operators chose to deploy it properly.
- hlandau 10y ago
  From what I've heard (I may be mistaken here), 2G/3G had pretty poor radio link security. This resulted, of course, in Stingrays. 4G supposedly has actually secure radio links; I think to the extent Stingrays work on these devices, it's by forcing a downgrade to 2G/3G. So as it becomes feasible to drop 2G/3G support Stingrays will stop working, although of course this will take a long time. That said, supposedly what encryption 2G/3G did use extended further into the core network, whereas the encryption that 4G uses terminates at the base station. Supposedly all providers which are implementing 4G are in practice encrypting the links from the base station to the rest of the network with IPsec, but this does mean that the traffic is unencrypted at the base station itself, which makes the base station vulnerable to physical compromise. Some people have criticised LTE's security over GSM/UMTS for this reason. On the whole I think it's a net gain, though. Physically compromising a base station is a higher friction and higher risk activity than deployment of a Stingray. Moreover, I can understand that it would be potentially troublesome to have an encrypted channel from the handset to deep in an operator's core network, since it forces all traffic to travel via that route, which would necessarily increase latency. Although in practice IIRC 4G traffic might still take the same route anyway due to the weird tunnelling architecture GSM/UMTS/LTE uses, so that might be a moot point. But the article seems to imply they're focusing on reducing latency, so it's possible they're changing that for 5G. Anyone know?
- at-fates-hands 10y ago
  Here's a good paper that came out in 2015 about LTE security that's worth a read: http://csrc.nist.gov/news_events/cif_2015/research/day2_research_200-250.pdf http://csrc.nist.gov/news_events/cif_2015/research/day2_rese.... It was put out by NIST (National Institute of Standards and Technology)
noselasd 10y ago
As someone that has written code to pick up the encryption keys out of the Diameter protocol, and used those to decrypt the control plane NAS signaling on the S1 interface, correlated this info with the user plane data between a S-GW and P-GW - no - LTE is not end to end encrypted. There's encryption between your mobile and a few nodes within the core network of your carrier - inside that network, you can easily break that encryption if you get hold of the keys - and those keys are communicated in plain-text between a couple of the network nodes (on the S6a interface). While those interfaces are supposed to be using IPSec, I've yet to see anyone doing that all the way. The radio interface, between your device and the cell tower is decently protected though. Unless you're in a country that demands the use of the EEA0 and EIA0 encryption algorithms (a.k.a. no encryption at all).
- lallysingh 10y ago
  It's a bit of a silly question. End-to-End is TLS. One end has to be the phone, and your other end is your destination host. Encryption through some part of the middle is only useful on the radio side -- the rest of the network is wired and has the same ("meh"-) level of security.
mtgx 10y ago
End-to-end encryption typically refers to "one user to another". Not from "one base station to another" or from "one carrier to another". It should've been quite obvious in the context of privacy.

pjc50 10y ago

Isn't it just mobile station to base station encryption, not true E2E encryption of calls (which would never be allowed)?

kristoffer 10y ago
No the core network uses IPSec. Of course there is support for "lawful interception" though.
- kristoffer 10y ago
  Or rather has support for IPSec, not all operators chose to deploy it properly.
hlandau 10y ago
From what I've heard (I may be mistaken here), 2G/3G had pretty poor radio link security. This resulted, of course, in Stingrays. 4G supposedly has actually secure radio links; I think to the extent Stingrays work on these devices, it's by forcing a downgrade to 2G/3G. So as it becomes feasible to drop 2G/3G support Stingrays will stop working, although of course this will take a long time. That said, supposedly what encryption 2G/3G did use extended further into the core network, whereas the encryption that 4G uses terminates at the base station. Supposedly all providers which are implementing 4G are in practice encrypting the links from the base station to the rest of the network with IPsec, but this does mean that the traffic is unencrypted at the base station itself, which makes the base station vulnerable to physical compromise. Some people have criticised LTE's security over GSM/UMTS for this reason. On the whole I think it's a net gain, though. Physically compromising a base station is a higher friction and higher risk activity than deployment of a Stingray. Moreover, I can understand that it would be potentially troublesome to have an encrypted channel from the handset to deep in an operator's core network, since it forces all traffic to travel via that route, which would necessarily increase latency. Although in practice IIRC 4G traffic might still take the same route anyway due to the weird tunnelling architecture GSM/UMTS/LTE uses, so that might be a moot point. But the article seems to imply they're focusing on reducing latency, so it's possible they're changing that for 5G. Anyone know?
at-fates-hands 10y ago
Here's a good paper that came out in 2015 about LTE security that's worth a read: http://csrc.nist.gov/news_events/cif_2015/research/day2_research_200-250.pdf http://csrc.nist.gov/news_events/cif_2015/research/day2_rese.... It was put out by NIST (National Institute of Standards and Technology)

noselasd 10y ago

As someone that has written code to pick up the encryption keys out of the Diameter protocol, and used those to decrypt the control plane NAS signaling on the S1 interface, correlated this info with the user plane data between a S-GW and P-GW - no - LTE is not end to end encrypted. There's encryption between your mobile and a few nodes within the core network of your carrier - inside that network, you can easily break that encryption if you get hold of the keys - and those keys are communicated in plain-text between a couple of the network nodes (on the S6a interface). While those interfaces are supposed to be using IPSec, I've yet to see anyone doing that all the way. The radio interface, between your device and the cell tower is decently protected though. Unless you're in a country that demands the use of the EEA0 and EIA0 encryption algorithms (a.k.a. no encryption at all).

lallysingh 10y ago
It's a bit of a silly question. End-to-End is TLS. One end has to be the phone, and your other end is your destination host. Encryption through some part of the middle is only useful on the radio side -- the rest of the network is wired and has the same ("meh"-) level of security.

mtgx 10y ago

End-to-end encryption typically refers to "one user to another". Not from "one base station to another" or from "one carrier to another". It should've been quite obvious in the context of privacy.