Implement signal's double ratchet

[0xdevalias]

I'm not sure of the feasibility/effort that would be required for this.. but it would be really interesting and cool to implement Signal's double ratchet algorithm:

• https://en.wikipedia.org/wiki/Double_Ratchet_Algorithm

From a quick google, maybe something like:

• https://github.com/rongarret/ratchet-js
  • https://github.com/dchest/tweetnacl-js/

[wisec]

@0xdevalias Thanks for your suggestion!
We'll look into it and see if it's feasible.