Comment on Wireshark: Facetime on Iphone 4: Vanilla unencrypted STUN and SIPparentComments−eli16yNo, not end-to-end, but they are encrypted between your phone and the cell tower.It's considerably more secure than an open wifi network.−sp33216yGSM supports optional encryption, but there's no notification to the user whether a given call is encrypted.−eli16yYes, but I'm pretty sure all US carriers use it all the time(Though it's true that this opens you up to a potential MITM attack by a well equipped adversary, it's still a far cry from an open wifi network)
Comments
No, not end-to-end, but they are encrypted between your phone and the cell tower.
It's considerably more secure than an open wifi network.
GSM supports optional encryption, but there's no notification to the user whether a given call is encrypted.
Yes, but I'm pretty sure all US carriers use it all the time
(Though it's true that this opens you up to a potential MITM attack by a well equipped adversary, it's still a far cry from an open wifi network)