The Comcast and Sprint logos.

Comcast and Sprint Start Rollout of Anti-Robocall Technology


Comcast and Sprint announced today the two companies are now utilizing call authentication technology that helps further protect customers from unwanted robocalls between Sprint mobile customers and Comcast’s Xfinity Voice landline phone customers.

Secure Telephone Identity Revisited (STIR) and Signature-based Handling of Asserted Information Using toKENs (SHAKEN) is a protocol that authenticates calls between networks. The technology enables voice providers to “sign” and “verify” caller ID information, thus preventing bad actors from manipulating or “spoofing” caller ID information in an effort to deceive and defraud consumers.

“This is a major milestone in the fight to help our customers protect themselves from unwanted robocalls that have become such a plague for the industry,” said Dr. John Saw, Sprint CTO. “Our engineers have worked diligently with the teams at Comcast to bring this to fruition, and with work already underway with additional providers, we look forward to rolling out STIR/SHAKEN jointly across other networks as soon as possible.”

“We’ve made great progress with our industry peers, like Sprint, in developing ways to thwart nuisance calls, and we will continue to work relentlessly to stop them from reaching our customers,” said Tony Werner, president of Technology, Product and Xperience for Comcast. “Every STIR/SHAKEN implementation between providers, or bi-partisan action to pass landmark legislation like the TRACED Act, is another step forward in protecting consumers.”

Following successful lab-to-lab tests last year, initial two-way authentication for calls began with a subset of customers in December 2019 and will roll out to all customers nationwide in the coming months.

Sprint also recently announced it is collaborating with T-Mobile to deliver STIR/SHAKEN call verification to customers. These rollouts supplement two additional STIR/SHAKEN authentication supplements two previously announced solutions for Sprint customers who are tired of bothersome robocalls, unwanted telemarketers, and annoying scams. Sprint Call Screener Basic is a free service that identifies unwanted malicious calls and permits users to block them. Sprint also offers a more feature-rich Sprint Call Screener Plus service for just $2.99 per month, per line. In addition to the services provided by the free service, Sprint Call Screen Plus also displays a texter’s name or a caller’s name, city and state, even those not listed in contacts; identifies, blocks, and reports calls that are lower-risk, but still a nuisance; categorizes incoming calls as spam, robocalls or fraud calls; reports an individual phone number as spam; and keeps history of blocked and risky numbers.

Comcast is a leader in the industry-wide effort to combat fraudulent calls. In addition to the collaboration with Sprint, the company recently completed the first international authenticated STIR/SHAKEN call between Xfinity Voice residential phone service and Canadian mobile provider, Telus Wireless. Comcast has also worked with major U.S. providers to conduct the first call between two landline voice networks, and the first end-to-end call across three networks, using the STIR/SHAKEN protocol. Additionally, Xfinity Mobile customers now can download the Hiya app for free to begin receiving alerts about potential spam calls and block them.