I want to open this thread since it seems quite passed under silence, in spite of the fact that the topic is full of possible discussions.

I will start with a question that came into my mind recently:
did the dwarves receive their language by their maker Aule
or did they develop it by themselves?

Maybe the fact that their fathers slept for a long time under the rocks remained impressed inside their heart, and a long memory -so to speak- is characteristic of their race,
I propose this as one source of the necessity ok keeeping
a secret way of communicating; yet it is not an answer to the question.

Aule give them their name Khazad, but as his project could not be hidden from Eru, so their true name had to be revealed to the other folks; again no answer.

Maybe, but this is only a conjecture, Aule put inside them his own knowledge and thaught them to exchange information in a secure way -to address the matter with a modern look-
which they then cultivated together with their ability in stoneworking and smithcraft.

What do you think?