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The Federal Communications Commission Thursday reiterated its demand that major phone carriers implement a standardized caller ID authentication network by the end of the year, a move that would aid in combating both scammers and the number of robocalls plaguing people’s phones.

According to YouMail, a software company that blocks robocalls, nearly 48 billion robocalls were made nationally in 2018—a roughly 19 billion increase from two years prior.

The FCC took a major step towards limiting these calls Thursday by voting to allow service providers block unwanted calls by default, so long as customers have the option to opt out of the service. Currently, blocking such robocalls is available on an opt-in basis, but many customers are not aware of this option.

Thursday’s vote also included a provision to require service providers adopt the caller ID authentication network known as SHAKEN/STIR, but only if the providers fail to do so voluntarily by the end of the year. A previous FCC statement on the matter argues self-implementation is likely the fastest way to help customers, as any regulatory mandates could be “bogged down in litigation.”

SHAKEN/STIR, which stands for Signature-based Handling of Asserted Information Using toKENs (SHAKEN) and the Secure Telephone Identity Revisited (STIR) standards, would help to prevent illegal caller ID “spoofing.” This is when a caller falsifies the information displayed on the caller ID, usually as way to trick the receiver into giving away personal information.

“Often, calls are spoofed to look like they are coming from a local business or neighbor,” said FCC Commissioner Geoffrey Starks in a statement. “This pernicious practice makes it so we can’t differentiate these unwanted robocalls from calls from our doctors or our kids’ schools.”

According to the FCC, the SHAKEN/STIR system would have the caller ID of calls traveling through interconnected phone networks “signed” as legitimate by the originating carriers and validated by other carriers before reaching consumers. This would not only ensure the caller ID is accurate, but would help to strengthen call-blocking systems.

FCC Chairman Ajit Pai first demanded the service providers implement such a system in November 2018. So far, he said he’s “pleased by the progress that industry has made” and is “optimistic that the end-of-the year deadline will be met.”

Following Thursday’s vote, the FCC said it will be seeking comment on whether a safe harbor should be made for providers that block robocalls based on whether the caller ID was authenticated. The agency will also be hosting a SHAKEN/STIR summit on July 11 to examine the phone industry’s progress towards implementing the standardized system.

FCC Takes Major Step Toward Limiting Robocalls and Scammers

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