Abstract: A method for the exchange between two computer systems, without prior exchange of any material or prior third-party endorsement, of key-pairs and signed public-key certificates for the purpose of establishing communications secure from eavesdropping or man-in-the-middle attacks; a mechanism for verifying the exchange was not subject to third-party eavesdropping or man-in-the-middle attack; and a mechanism for verifying future communication using the exchanged material is occurring between the two computer systems involved in the original exchange.