How Phone Companies Are Finally Verifying Caller ID Numbers

Robocalls are a scourge, leaving many people unwilling or afraid to pick up their phone unless they know the caller. If you’re waiting for a job interview or support callback, this is incredibly stressful—but now phone carriers are helping.

New Standards Will Unmask Spoofing

If you have T-Mobile service and a Galaxy S9, soon you will start seeing “Caller Verified” when calls arrive, if T-Mobile can verify the caller ID matches the real phone number. The Caller Verified message means that the call originated from T-Mobile, and they can confirm that no spoofing or intercepting occurred in placing the call.

Verifying calls relies on a new standard called STIR (Secure Telephone Identity Revisited) and SHAKEN (Signature-based Handling of Asserted information using toKENs). Not to be confused with martini preparation directions, STIR/SHAKEN will allow phone carriers to determine if the number a call identifies with is real. Current caller ID technology doesn’t have any method to determine if the information provided is accurate and STIR/SHAKEN will solve that problem.

And as other carriers implement STIR/SHAKEN, they will work together so that phone calls verification occurs even when they come from a different carrier.

Additionally, T-Mobile, Verizon, and others are already offering blocking services that rely on crowdsourced blacklists. Robocaller blocking has been free on AT&T since 2016, free on T-Mobile since early 2017, and now Verizon has announced they will no longer charge for call filtering starting next March.

man wearing gray shirt use blue Samsung S9 plus — Noyna/Shutterstock

You May Already Have Some Spam Blocking

Crowdsource based spam blocking software is already ubiquitous, and chances are you can either subscribe to it from your carrier or download an app for your phone that will achieve the same goal. But the new STIR/SHAKEN standard will take longer to implement fully.

If you have T-Mobile and a Galaxy S9, you have the first stages of the technology right now and ‘more devices’ will receive STIR/SHAKEN in 2019. Meanwhile, Verizon and AT&T have promised to implement, but not specified an exact timeline beyond 2019. Sprint has made no such promises and instead questioned the cost and effectiveness.

Apple, Google, and other phone manufacturers haven’t commented on any plans to assist with the implementation of the standard. Microsoft supports SHAKEN/STIR and helped in its development. While they aren’t working on Windows Phone anymore, they do have an interest through Skype.