@techreport{wendt-stir-vesper-02,
    number =    {draft-wendt-stir-vesper-02},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-wendt-stir-vesper/02/},
    author =    {Chris Wendt and Robert Śliwa},
    title =     {{VESPER PASSporT and Identity Tokens - VErifiable STI Personas}},
    pagetotal = 46,
    year =      2024,
    month =     oct,
    day =       22,
    abstract =  {This document extends the STIR architecture by defining a Personal Assertion Token (PASSporT) with a type of "vesper" (VErifiable Sti PERsona) and specifies the use of PASSporTs as a JSON Web Tokens (JWT) and Selective Disclosure JWT (SD-JWT) for representing verifiable claims related to a persona (a person or business entity) associated with a Secure Telephone Identity (STI). This set of extensible claims can include verifiable information such as the assignment of a telephone number, the output of a Know Your Customer (KYC) or Know Your Business (KYB) type of vetting process, Rich Call Data (RCD) or claims of consent provided to the telephone number holder. The architecture, dependencies, and process flow of Vesper includes logical roles that represent certain responsibilities for establishing a secure telephone identity. These roles represent the basis for trusted relationships to information that is being claimed and who is validating and taking responsibility for the accuracy of that information. These roles begin with a Subject Entity (SE) that is the end entity that intended to be represented by the STI telephone number identifier. A Vetting Claim Agent (VCA) establishes the Subject Entity as a vetted entity after performing the initial vetting and existence as a entity that fulfills the criteria and policies of the ecosystem to be associated with an STI. A Notary Agent (NA) is a neutral role that maintains a graph of relationships among all roles, claims, and identities, but importantly, for protecting privacy, doesn't hold any claim information other than the recording of claim events to the STI telephone number. The NA records these claim event transactions with a corresponding transparency log that generates verifiable receipts to "notarize" the recording of these relationships and claims being established. Privacy is enabled in this Notary role because the submitters have the option of submitting hashes of claims to protect information, or may usefully want to publicly declare their association to a claim to allow the public monitoring to avoid duplicate, mistaken or negligent claims which can be identified before illegitimate usage in the eco- system can occur. Other Claim Agents are defined producing claims in the form of SD-JWT + receipts from the NA. There are multiple claim agent types with corresponding extensible claim definitions with key value pairs that can be required or optionally included. These SD- JWT + receipt claim objects are then collected by the SE into a digital wallet that it can then use for selective disclosure presentation and incorporate into a "vesper" PASSporT signed by the a delegate certificate associated with STI telephone number to validate the SE is indeed the authorized holder of the telephone number and vesper token at the time the presentation is required and ties the SE to the STIR eco-system a STIR certificates policy for use in communications.},
}