If it could exist during our lifetime, assuming the capture and storage of encrypted message streams is trivial to well resourced threat actors (nation states), if the cost is reasonable to implement quantum mitigations it is reasonable and prudent from a risk management perspective to do so.

The worst case scenario is nation states consuming and storing these encrypted message streams, and suddenly achieving the ability to rapidly decrypt everything previously captured and stored a la "No more secrets."

Doesn't mean that it won't exist in the future (I'm not sure if this was meant to be negative towards Signals efforts here)

Yeah let's only start work once it's too late. That'll teach em!

amen