While I'm not aware of any serverless signalling solution that includes support for stuff like Trickle ICE, at least there are trustless E2E-encrypted solutions

While I'm not aware of any serverless signalling solution that includes support for stuff like Trickle ICE, at least there are trustless E2E-encrypted solutions like https://saltyrtc.org/ https://saltyrtc.org/ (Disclaimer: I'm involved, but it's an open source project.)