Theorycrafting without a real idea here but how about a physical device with private keys and challenge-response authentication from a site. To login you have t

Theorycrafting without a real idea here but how about a physical device with private keys and challenge-response authentication from a site. To login you have to press a button to sign a specific message as a specific person. Then they can't silently gain access to your account persistently. They can gain access until you logout but then they have to wait for you to login again. Or they can change the key but then you'd notice that you can't login.