Earlier today CNN reported that "As of Thursday the square, cylindrical device will now recognize partners, roommates, kids and guests who come to visit. So when you say the trigger phrases "OK Google" or "Hey Google," the Google Home device will listen for who is asking and provide answers based on your voice. For example, Google Assistant will know what's on your calendar, what your reminders are and what your commute looks like. On the other hand, it will likewise know when someone talking to it doesn't have a profile, preventing personal data being read aloud to someone it doesn't belong to. For instance, if a guest asks what someone's calendar looks like, Google won't read it.

Even though Apple filed a patent for this feature for Siri back in 2016 that was published earlier this month, the fact is that Google filed for their patent back in 2015. The "trigger phrases" that CNN notes in their report are officially considered "hotwords" in their patent filing.

One key aspect of Google's patent states the following:

"Implementations of the present disclosure relate to hotword recognition, for example, using a hotword to unlock or enable access to a mobile device via voice, and inhibiting replay attacks."

So what's a replay attack? Google defines it this way: "A replay attack is the process by which an unauthorized user captures the audio for a hotword spoken by the device's owner or authorized user, and replays it in order to gain some level of unauthorized access to the device.

According to implementations of the invention, hotwords or any speech-based replay attacks may be inhibited by verifying the uniqueness of each utterance that is stored.

An audio fingerprint may be generated and stored for each hotword utterance, and a comparison may be performed between the audio fingerprint generated from a new utterance with each previously recorded audio fingerprint to check whether the same utterance audio has been previously used, indicating a replay.

In addition, in certain implementations, other signals, e.g., ultrasonic audio injection and cross-utterance verification may be used to further limit the effectiveness of replay attacks.

Google's patent FIG. 1 depicts an example system for detecting and verifying a hotword; FIG. 2A depicts a diagram of an example process for detecting and verifying a hotword.

Google's patent application that was originally filed back November 2015 surfaced today at the U.S. patent and Trademark Office.

Patently Mobile presents a detailed summary of patent applications with associated graphics for journalistic news purposes as each such patent application is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent application should be read in its entirety for full and accurate details. About Posting Comments: Patently Mobile reserves the right to post, dismiss or edit any comments. Those using abusive language or behavior will result in being blacklisted on Disqus.