Signal message keys seem to include an IV. [1] Message keys are generated by passing a chain key through a key derivation function. [2] So you can also expand a

Signal message keys seem to include an IV. [1] Message keys are generated by passing a chain key through a key derivation function. [2] So you can also expand a shared secret established through Diffie-Hellman. Someone please correct me if I'm wrong. [1] https://github.com/signalapp/libsignal-protocol-java/blob/master/java/src/main/java/org/whispersystems/libsignal/ratchet/MessageKeys.java https://github.com/signalapp/libsignal-protocol-java/blob/ma... [2] https://signal.org/docs/specifications/doubleratchet/Set0_1.png https://signal.org/docs/specifications/doubleratchet/Set0_1....