Provenant, Inc Verifiable Voice Protocol (VVP) authenticates and authorizes organizations and individuals making and/or receiving telephone calls. This eliminates trust gaps that malicious parties exploit. Like related technologies such as SHAKEN, RCD, and BCID, VVP uses STIR to bind cryptographic evidence to a SIP INVITE, and verify this evidence downstream. VVP can also let evidence flow the other way, proving things about the callee. VVP builds from different technical and governance assumptions than alternatives, and uses richer, stronger evidence. This allows VVP to cross jurisdictional boundaries easily and robustly. It also makes VVP simpler, more decentralized, cheaper to deploy and maintain, more private, more scalable, and higher assurance. Because it is easier to adopt, VVP can plug gaps or build bridges between other approaches, functioning as glue in hybrid ecosystems. For example, it may justify an A attestation in SHAKEN, or an RCD passport for branded calling, when a call originates outside SHAKEN or RCD ecosystems. VVP also works well as a standalone mechanism, independent of other solutions. An extra benefit is that VVP enables two-way evidence sharing with verifiable text and chat (e.g., RCS and vCon), as well as with other industry verticals that need verifiability in non-telco contexts.