Every computer you sign in on gets its own SSH key, and all your Kisten accept all of them.
You never copy SSH keys around. Every computer you sign in on with
kiste login creates its own SSH key, stored only on that computer, and adds
its public half to your account. Every Kiste of your account accepts every one
of these device keys, including Kisten created before you signed in on that
computer.
How keys reach your Kisten
kiste.run installs your account's current device keys into a Kiste when it is
created or resumed, and again before every SSH connection. A key you removed
stops working at the next of these. The keys live in a managed block of
/root/.ssh/authorized_keys; lines you add yourself outside that block are left
alone.
Signing out
kiste logout revokes the computer's sign-in and removes its device key from
your account. kiste logout --local only forgets the sign-in on this computer,
for when kiste.run can't be reached; remove the key later with
kiste devices remove.
Limits
An account can have 50 device keys (L09). Browser sessions never add keys; only a CLI sign-in does.
A lost computer
Remove its key with kiste devices remove ID from any other signed-in computer, and
end its sign-in in the console or with sign out everywhere.