How Meet encrypts information
Hangouts Meet video meetings are encrypted in transit so that the information is secure. This includes video meetings on a web browser, on the Hangouts Meet Android and iOS apps, and in meeting rooms through Hangouts Meet Hardware.
To improve audio and video quality, Hangout video meetings may use a direct peer-to-peer connection when this is more efficient than routing the media traffic through Google’s servers.
Audio and video in Hangouts Meet are encrypted using SRTP_AES_CM_128_HMAC_SHA1_80 (128-bit AES encryption and SHA-1 HMAC for authentication).
When you dial a phone number to join a video meeting audio follows the regional telephone carrier’s network and may not be encrypted.