Thank you for a great question! One thing that comes to my mind while using public channels like this is to use TweetNaCl.js which allows easy public-key authenticated encryption.

So, first, let me generate a random new keypair by pressing Random button at the link above. Now I note My Secret Key which I keep private. My Public Key is Tg97OKc4MrGAnIUqq6uvTdtBj75OGRdWv5XpiP/9nC8=. Now you please do the same and write me your public key here in unencrypted text. You can also generate a random nonce which we will use for our first message.

Once we establish an encrypted "channel" using public unencrypted stacker.news comments, we can already share another means of communication (email or whatever else) without posting it publicly.

I hope you like this introductory Practical Encryption non-interactive session. Write to you soon!