%% You should probably cite rfc7340 instead of this I-D.
@techreport{ietf-stir-problem-statement-04,
    number =    {draft-ietf-stir-problem-statement-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-stir-problem-statement/04/},
    author =    {Jon Peterson and Henning Schulzrinne and Hannes Tschofenig},
    title =     {{Secure Telephone Identity Problem Statement and Requirements}},
    pagetotal = 25,
    year =      2014,
    month =     may,
    day =       9,
    abstract =  {Over the past decade, Voice over IP (VoIP) systems based on SIP have replaced many traditional telephony deployments. Interworking VoIP systems with the traditional telephone network has reduced the overall security of calling party number and Caller ID assurances by granting attackers new and inexpensive tools to impersonate or obscure calling party numbers when orchestrating bulk commercial calling schemes, hacking voicemail boxes or even circumventing multi- factor authentication systems trusted by banks. Despite previous attempts to provide a secure assurance of the origin of SIP communications, we still lack of effective standards for identifying the calling party in a VoIP session. This document examines the reasons why providing identity for telephone numbers on the Internet has proven so difficult, and shows how changes in the last decade may provide us with new strategies for attaching a secure identity to SIP sessions. It also gives high-level requirements for a solution in this space.},
}