Research And Implementation Of Media Protection Over Secure VoIP Based On SIP

VoIP can be defined as the ability to make phone calls and to send faxes over datanetworks with a suitable quality of service and much superior benefit. The research onproviding VoIP with the suitable security without affecting the performance of thistechnology is not enough.Based on the introduction of some protocols and related security services formedia protection over secure VoIP, this thesis presents a new solution to these issues,providing a secure model for VoIP that minimizes the processing costs and thebandwidth consumption. This is mainly achieved by making use of high-throughput,low packet expansion security protocol (SRTP), high-speed encryption algorithms(AES) and key management protocol (MIKEY), specifically oriented to supportreal-time transport protocol. Finally, the protocol SRTP and MIKEY was implementedand incorporated into a SIP user agent.This thesis presents the design of real-time transport protocol and keymanagement protocol, the model that two protocols work in coordination, and thedesign of mapping MIKEY to SIP for distributing keys. Finally, we choose C++ toimplement the solution.After summarizing the measurement results, this thesis has a conclusion that thethe media processing delay during call establishment this solution causes is relativelylittle. The overhead of encrypting a 20ms unit of data only takes about 0.25ms, and ittakes about 0.33ms to do the per packet authentication processing. It is obvious that thissolution can well protect VoIP media, and setup a secure conversation for users.