Yeah, so the following actually is valid: If all pairs of horses are the same color, all horses are the same color. Just starting the induction one step further.
I'm not saying that a single bot hasn't gotten through, but probably you're referring to the auto filled profiles? It's just a way for them to be non-empty.
The sanest option in terms of user practicality to me appears to be storing the private key on the server, maybe encrypted with the user's password, and sending it to the user on successful login where it would be decrypted client side.
That does seem reasonable, but it doesn't solve the trust issue. The server might always send a modified script that just uploads the plaintext private key.
That said it would still be useful in other ways. Like in a breach the data would be secure.
Yeah, so the following actually is valid: If all pairs of horses are the same color, all horses are the same color. Just starting the induction one step further.