Which VoIP protocol provides for end-to-end secure communications by requiring user authentication?

Answer 1

The VoIP protocol that provides for end-to-end secure communications through user authentication is the Secure Real-time Transport Protocol (SRTP). SRTP enhances the standard Real-time Transport Protocol (RTP) by adding encryption, message authentication, and replay protection, ensuring that both the media and signaling aspects of VoIP communications are secure. Additionally, protocols like SIP (Session Initiation Protocol) can work alongside SRTP to establish secure sessions through authentication mechanisms.