5 ms·

Does this only affect 2G/EDGE for the most part? Because I know that T-Mobile falls back on 2G more often than AT&T does. The only time I’ve been on 2G with AT

Does this only affect 2G/EDGE for the most part? Because I know that T-Mobile falls back on 2G more often than AT&T does. The only time I’ve been on 2G with AT&T in the last few years was going through the BART tunnel in South Bay… haha.

esturk 12y ago
There's a tunnel in South Bay? Don't you mean East Bay near Oakland?
- freshchilled 12y ago
  He probably just means he was underground. Not the Transbay tube
  - AnimalMuppet 12y ago
    IIRC, there is a fairly lengthy tunnel on the line down to SFO.
    - largote 12y ago
      That is nowhere near the South Bay though.
largote 12y ago
BART in the South Bay, huh? Sounds legit.
- benguild 12y ago
  ... Yes. South San Francisco on the way to the airport. If it's South SF isn't that South Bay? Who drew the line and where :P
  - Apocryphon 12y ago
    Probably Sunnyvale. South S.F. is definitely the Peninsula at least, if not considered part of the city.
  - largote 12y ago
    It's not the South Bay until you are at least in Santa Clara county.
BuildTheRobots 12y ago
A5/3 (Kasumi) is near-on identical to the cyphers used in 3G connections, but you're right, this is the 2G only implementation; so yes, this only affects (applies to) 2G/EDGE/GSM. I'm absolutely bloody agog that commercial first-world operators have taken until the end of 2014 to actually support this -I think it was ratified into the specification around 2001 if not earlier. Also, for all you tinfoil wearers out there, you might like the fact that the original specification for A5/3 was altered to make it more hardware friendly. In 2010 it was realized that this actually made it extremely easy [1] to recover the session key (if not in real time) [2]. [1] core2due in a couple of hours easy, see the abstract [2]. [2] http://eprint.iacr.org/2010/013 http://eprint.iacr.org/2010/013
- droopybuns 12y ago
  A5/3 is a block cipher, 3G connections use a stream cipher. Respectfully, this is not "near-on" identical. http://security.stackexchange.com/questions/334/advantages-and-disadvantages-of-stream-versus-block-ciphers http://security.stackexchange.com/questions/334/advantages-a... Integrating support for these algorithms on the device side ends up being a high hurdle. Doing anything at scale is inevitably harder than you expect it to be. If it was a simple change, people would make it.
  - BuildTheRobots 12y ago
    THanks for the clarification, I'm obviously getting myself confused somewhere. /me goes back to the documentation.
offmycloud 12y ago
Unless you are using VoIP, all of your voice calls go over the 2G network.
- kalleboo 12y ago
  You're mistaken - 3G/UMTS supports circuit-switched voice calls just fine. It's 4G/LTE that hasn't supported voice calls until very recently when the first networks deployed VoLTE.

esturk 12y ago

There's a tunnel in South Bay? Don't you mean East Bay near Oakland?

freshchilled 12y ago
He probably just means he was underground. Not the Transbay tube
- AnimalMuppet 12y ago
  IIRC, there is a fairly lengthy tunnel on the line down to SFO.
  - largote 12y ago
    That is nowhere near the South Bay though.

largote 12y ago

BART in the South Bay, huh? Sounds legit.

benguild 12y ago
... Yes. South San Francisco on the way to the airport. If it's South SF isn't that South Bay? Who drew the line and where :P
- Apocryphon 12y ago
  Probably Sunnyvale. South S.F. is definitely the Peninsula at least, if not considered part of the city.
- largote 12y ago
  It's not the South Bay until you are at least in Santa Clara county.

BuildTheRobots 12y ago

A5/3 (Kasumi) is near-on identical to the cyphers used in 3G connections, but you're right, this is the 2G only implementation; so yes, this only affects (applies to) 2G/EDGE/GSM. I'm absolutely bloody agog that commercial first-world operators have taken until the end of 2014 to actually support this -I think it was ratified into the specification around 2001 if not earlier. Also, for all you tinfoil wearers out there, you might like the fact that the original specification for A5/3 was altered to make it more hardware friendly. In 2010 it was realized that this actually made it extremely easy [1] to recover the session key (if not in real time) [2]. [1] core2due in a couple of hours easy, see the abstract [2]. [2] http://eprint.iacr.org/2010/013 http://eprint.iacr.org/2010/013

droopybuns 12y ago
A5/3 is a block cipher, 3G connections use a stream cipher. Respectfully, this is not "near-on" identical. http://security.stackexchange.com/questions/334/advantages-and-disadvantages-of-stream-versus-block-ciphers http://security.stackexchange.com/questions/334/advantages-a... Integrating support for these algorithms on the device side ends up being a high hurdle. Doing anything at scale is inevitably harder than you expect it to be. If it was a simple change, people would make it.
- BuildTheRobots 12y ago
  THanks for the clarification, I'm obviously getting myself confused somewhere. /me goes back to the documentation.

offmycloud 12y ago

Unless you are using VoIP, all of your voice calls go over the 2G network.

kalleboo 12y ago
You're mistaken - 3G/UMTS supports circuit-switched voice calls just fine. It's 4G/LTE that hasn't supported voice calls until very recently when the first networks deployed VoLTE.