It can be toxic here too. I had my misadventure with a bunch of “experts” absolutely sure that the future is communism and “stupid you brainwashed fool” if you don’t get it.

It happened to me at work and it was a very bad period. Even if it ended well for me, no forgiveness.

It’s probably wrong to assume that the general public will be sensitive enough to privacy to force companies to compete on that terrain.

But it’s a fascinating topic and I hope to see it in practice at some point.

your gpg example removes the deniability since it proves who wrote the message.

You confuse digitally signing a message with the sender’s private key, and encrypting a message with the recipient’s public key.

A shared secret implies that the message was sent by someone who knows the shared secret, and that restrict the number of potential senders.

If you mail a message with gpg, everyone knows the public key, and the message is still safe.

The knowledge of a shared secret suggests that the message could be authentic. It makes more sense to use asymmetric encryptions (without signatures).

A flag should be easy to draw: I’d replace the hand with a stylized fingerprint.