Comment by tharkun__

Challenge: make it possible to use something like Diffie Hellman[0] to exchange a key securely even over an unsecure channel but where they resulting key is actually the password to type in and "reads" like https://xkcd.com/936/ i.e. something my grandma could type in. Without reducing the key space too much to be insecure ;)

[0] https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exc...