To nit-pick a tad more, when they have access to my key and have my passphrase so they can sign with it…
That’s why you set the passphrase on keys, gpg, ssh,… Never use a encryption without a key. That way you need posession (key) and knowledge (passphrase) to identify yourself. When you use ssh, use the ssh agent, when you have automated login which would be better to use without keyphrase, use a different pair (specify wuth -i option) and limit access with that to a fixed ip.
And always protect your key. No cloud backup…
Edit: GPG keys also can be signed. Not by specific companies (there is probably a service for that, but it’s not by design), but by other people knowing each other. That way you have a trust based on who knows who, not who has more cash…
Same with ssh keys, you can sign those as well and set sshd to accept anybody with a certificate signed by ‘x’ to access the server on the same account name the cert was issued for.
To nit-pick a tad more, when they have access to my key and have my passphrase so they can sign with it…
That’s why you set the passphrase on keys, gpg, ssh,… Never use a encryption without a key. That way you need posession (key) and knowledge (passphrase) to identify yourself. When you use ssh, use the ssh agent, when you have automated login which would be better to use without keyphrase, use a different pair (specify wuth -i option) and limit access with that to a fixed ip.
And always protect your key. No cloud backup…
Edit: GPG keys also can be signed. Not by specific companies (there is probably a service for that, but it’s not by design), but by other people knowing each other. That way you have a trust based on who knows who, not who has more cash…
Same with ssh keys, you can sign those as well and set sshd to accept anybody with a certificate signed by ‘x’ to access the server on the same account name the cert was issued for.