Google has quietly added a new setting called Verified SMS that will prevent users from receiving spam via SMS. Google Message beta’s new feature, ‘Verified SMS’ is meant at protecting you from unwanted spam text messages or potential phishing attempts.
When an SMS appears to be sent by a verified business the feature potentially works then. Google uses authenticity codes to verify each SMS that you receive to alert you from any spoofing attempt or misleading content, hence saving you from clicking on dangerous links or giving away your sensitive information to goofy sites.
This verification uses a unique hash based on your phone number, the business, and the message's content. Every unique hash is created on your device and then sent to Google which compares it against the one it received in parallel from the verified business.
Google uses authenticity codes in order to verify each SMS received to see if the message received is spam or from a spoofed telephone number. In this way, Google expects that it should protect against any potentially harmful content or phishing attempts.
To use the new feature go the Messages app, you'll find a new toggle in Settings -> Verified SMS. The option is enabled by default, but you can turn it off if you'd rather not use it. However, the new feature is currently only available in the United States.