The twin plagues of text-message spam and robocalls have been teaching phone users a harsh lesson: Trust no one.

While measures to block those annoyances grind

While measures to block those annoyances grind on, two efforts are proposing a different solution that amounts to “trust someone.” They take the blue-checkmark approach of social networks that verify users and apply it to texts and calls from legitimate businesses.

The higher-profile venture comes from Google, which on Dec. 12 announced what it calls Verified SMS. The technology lets participating businesses send texts that arrive in Google’s Messages app for Android with the logo and title of their choice, plus a checkmark verification badge.

This happens without Google seeing the content of any messages. Instead, a company’s agent app and its customer’s Messages app send paired encryption keys and then compare “hashes”—mathematical abstractions of the message—to confirm that both the sender and the content match. This required exchange necessitates a data connection, which is not true of garden-variety SMS.

Google lists 1-800 Flowers, Banco Bradesco, Kayak, Payback, and Sofi as participating firms; it’s also using Verified SMS to send its own two-step verification text messages. One of the firms providing Verified SMS services, the business-communications company Twilio, lists Expensify as another early adopter.

“As rich channels for business messaging (WhatsApp, RCS, Messenger, and so on) pop up with features like profile branding and verification, SMS has to keep up,” said Simon Khalaf, Twilio’s senior vice president and general manager for messaging, in an email sent by a publicist. He added that Twilio isn’t “currently” charging for the technology.

The big catch is that Verified SMS only works with Google’s own Messages app. It isn’t compatible with the one Samsung provides on its Galaxy phones—and certainly not with Apple’s Messages app. So it’s even more limited in its potential audience than RCS messaging, the long-stalled update to text messaging that Google has been pushing wireless carriers to support.