A method for use in a peer-to-peer communication system to ensure valid connections are made in a secure manner includes the steps of receiving an address record for a peer node which includes an ID certificate. The ID certificate is validated and checked to verify that the ID certificate has not expired. Further, the method determines if the node from whom the address record was received is to be trusted, and the number of instances of the IP address included in the certificate is already stored in cache. When the foregoing are completed successfully, i.e. the certificate is valid, not expired, has been supplied by a trusted neighbor, and does not point to an IP address that already exists for different ID's multiple times, the method opportunistically verifies ownership of the ID certificate at the peer node's IP address. That is, the verification of ownership only occurs when the advertiser of the ID is the owner of that ID (or when the ID is to be used). If any of the above cannot be completed successfully, the address record is discarded.