Surely it is no good idea to log into a remote system from an untrusted computer. But sometimes it is plain necessary. Exposing an unencrypted SSH keyfile is no option of course. Entering a regular password is none either.
S/Key seems to be the "usual" solution but it requires strictly following the order of passwords on a list. This is undesirable for shared accounts as all parties would need to synchronize use of the list.
Any way to make OTPs with no requirements regarding order of usage? Other ideas?
Background: Two admins share an account. Another one should be given an "emergency envelope" that is sealed and contains information for that account. Breaking the seal is allowed only in case the other admins are unavailable.