Page tree
Skip to end of metadata
Go to start of metadata

You are viewing an old version of this page. View the current version.

Compare with Current View Page History

Version 1 Current »

Question: I got this error message while trying to dial a ZRTP secure call. What does it mean?

Answer: Each device is identified by ZRTP-ID (a auto generated identifier, generated once at install time) and also by mobile phone number (CLI). When you mark the other peer as "trusted" you are marking the couple <ZRTP-ID, CLI> as trusted in your device memory.

Upon secure call, ZRTP-ID and CLI are checked for trustiness. If only one of this two changed (e.g.: SIM exchange,  uninstall/install PrivateGSM -> a new ZRTP-ID is generated) we face a situation similar to what an MiTM attacker could try. For security reason, PrivateGSM warns that this situation, could be both valid and legal or a MiTM attack. So, secure call is hanged and you are forced to re-check SAS (Short Authentication Strings) to validate the other peer trust.

 

  • No labels