RFC 9475: Messaging Use Cases and Extensions for Secure Telephone Identity Revisited (STIR)
Recent RFCs 2023-12-19
Summary:
Secure Telephone Identity Revisited (STIR) provides a means of
attesting the identity of a telephone caller via a signed token in
order to prevent impersonation of a calling party number, which is a
key enabler for illegal robocalling. Similar impersonation is
sometimes leveraged by bad actors in the text and multimedia
messaging space. This document explores the applicability of STIR's
Personal Assertion Token (PASSporT) and certificate issuance
framework to text and multimedia messaging use cases, including
support for both messages carried as a payload in SIP requests and
messages sent in sessions negotiated by SIP.