What are “deadman’s keys”?
deadmans keys are software programs that have to be logged into on a regular basis or they execute a command. Perhaps, in this case, posting encryption keys to Twitter for sharing of Hillary’s missing 33,000 emails. Associates got the message and encryption to release the emails or download them from other servers in different countries.
Similar to a house alarm, when you walk in, it has to have a code to disarm, or the alarm goes off.