STIR/SHAKEN are acronyms for the Secure Telephone Identity Revisited (STIR) and Signature-based Handling of Asserted Information Using toKENs (SHAKEN) standards. They’re technical frameworks that measure trust in the displayed caller name and number by authenticating the calling number. Together they work in a way similar to attesting to the identity of the caller with a digital certificate. In the STIR/SHAKEN framework, a secure telephony identity (STI) governance authority issues digital certificates to carriers, or others who own or are assigned dedicated telephone numbers. The private key associated with a digital certificate is then used to sign a VoIP call, thereby indicating that the calling party number is who they claim to be.

The number of unwanted and illegal robocalls in the US continues to rise. Americans were hit by just under 46 billion robocalls in 2020, with about 40% of those calls thought to be fraud-related. And as annoying as these calls are for people who receive them, they’re even more detrimental for businesses that are trying to reach people with pertinent information. Many of these robocalls use caller ID spoofing to make recipients think they might know the caller. Caller ID spoofing hurts legitimate businesses by making call recipients less likely to pick up any calls.