You might have better expository skills than Salutator, and people love learning esoteric things about mysterious professions in the midst of fiction. Diffie-Helman relies on certain properties of math in prime modulus groups, but understanding those properties isn't necessary just to do DH. It only takes primary-school level math abilities to follow the example on Wikipedia (and note that, if nobody has computers, you don't need a 2048 bit modulus.