Abstract: A system, various methods, and various apparatuses are provided for the purpose of supplying and including in an electronic message or multimedia session signalling unit a valid cryptographic authentication token, verifying said token's validity upon arrival of said message or signalling unit, and thereby providing message recipients or session parties with the assurance that said message or signalling unit is from a valid sender. A system, apparatus, and various methods are further provided for the purpose of protecting legitimate application traffic and the network elements exchanging it from intrusion by wild packets attempting to consume application resources and thereby deny service to legitimate users or network elements.