WO-man in the middle.
Imma edit wikipedia right now
You are the man!!
WO-man that is.... wait are you man?
man in the middle is when somebody sits in the middle of a connection.
if it were not for "trusted authorities" when certs are initially exchanged, somebody could swap out the certs with their own, so the man in the middle could read the messages and re encrypt them with his keys that they also both had.
it may sound confusing, but thats why we have verisign and other idiots running around doing nothing but signing shit with their certs for large sums of capital, sometimes thousands for a single signature.