Call security

Calls without translation

Between two phones that support it, each call gets its own key, sent to the other phone through your encrypted chat. The media server relays audio and video it cannot decrypt, and a lock on the call screen shows that the call is end-to-end encrypted.

The media server software runs on AiThao’s own server. When no direct path between the two phones can be set up, the media may also pass through a relay run by a third party.

Transport encryption is not the same thing

All call media is encrypted in transit, as WebRTC requires. On its own that would still let the media server read the call. What makes a call end-to-end encrypted is the per-call key that the server never has.

Calls with translation

Translation on a call starts only when both people agree. To translate, the call’s key is given to AiThao’s translation worker so it can hear the call. From that moment the call is not end-to-end encrypted, and the lock on the call screen disappears.

Decoded audio goes to a translation provider; video is never sent to it. The key is kept for the call, at most about an hour.

What is kept about a call

• Calls are not recorded.
• A call log (who called whom, when and for how long) is kept for 90 days so you can see your call history.
• Call summaries: in a translated call, either person can ask for a summary, and the other sees that it is on. The written transcript goes to a cloud AI provider; AiThao stores neither the transcript nor the summary. You can refuse summaries of calls with you in Settings.