This article will explore Google’s voice technologies, the rising rates of adoption, and the implications for the digital forensics investigators and examiners who must contend with an expanding digital arena of direct and circumstantial evidence.

The voice command “OK Google”* can be used by digital forensics to unlock mobile devices with Cellebrite UFED Cloud. This solution enables digital forensics to unlock and extract this data, even if they only have the voice file of the suspect.

Google has designed an entire array of smart devices to recognize this simple voice command, potentially unlocking an entire ecosystem of Google products. For criminal cases suffering from ambiguous testimony or a scarcity of incriminating evidence, this access and voice file repository can produce a potential gold mine of corroborative digital evidence.

“OK Google” Voice Command Used for Initial Set Up and Access of Mobile Devices

As Google encourages global consumers to opt for voice commands, this simple two-word phrase is the start of the journey so many new mobile and smart device users will make.

Surprisingly, Russia almost leads the way in usage of the voice command, “OK Google”, followed by many other countries in that part of the world.




In fact, it has become increasingly common for people to use the phrase, “OK Google set up my phone,” during new device startup sequences. This initial experience is recorded and benchmarked in files that are later referenced by the mobile operating system to verify the owner. These same files are accessible during investigations, using the Cellebrite UFED Cloud that parses data provided by Google My Activity.

Top countries using the phrase “OK Google set up my phone”:




It is also well known now that Google is storing the sentence “OK Google” plus the adjoining question or request on the cloud. This log can prove invaluable in investigative scenarios, as the combination of intent with the voice of the user increases the perceived authenticity of digital evidence when examined.

When suspects prove uncooperative and a search warrant has been issued, investigators can exercise other creative methods such as recording an investigation to splice words together in order to unlock phones and other smart devices. As long as “OK” and “Google” are clearly mentioned, this technique could prove valuable.

Another capability – revealed at the recent Hacking Convention DEFCON – allows an investigator to record a suspect’s voice, then use machine learning to reproduce their “OK Google” voice command. This will be recognized by the suspect’s mobile device even without them actually saying those words. Although this seems like science fiction, the technology is already here.

Google Assistant at the Center of it All

At least once a month, over 35 million Americans use a voice-activated assistant device  —a year-over-year increase of 129%. On the heels of this rapid adoption,  Google reports that their Google Assistant app – activated by the OK Google voice command – has reached the milestone of having become available on over 400 million devices, including Google Home Speakers, Android phones, iPhones, TVs, watches and more.

As a result, Google Assistant is poised to become the digital doorman and fulfillment officer for so many actions and requests, especially for a growing number of millennial users who take this functionality for granted. This digital behavior will lead to a completely new arena of personal transparency for investigations.

The number of millennials who use voice-enabled digital assistants is set to climb to almost 40% in 2019. It has also been determined that at least once a month, almost 36% of millennials use voice-enabled digital assistants.

Google Assistant is also a multi-lingual offering that allows third-party integrations that lead to a consolidated management of a person’s entire digital life, that may include products above and beyond Google products.

And if you’re a user of older phones (Android 4.3 or lower), Google has not ignored you.  These users get support for devices running on older operating systems such as Android Lollipop.

Voice Commands Triggering Google Pay

Google Pay is Google’s digital wallet technology that powers in-app and tap-to-pay purchases on mobile devices; allowing users to make purchases with Android phones, tablets or watches.

Once Google Pay is set up on an iOS or Android phone, additional features enable money to be easily sent or requested from people using Google Assistant, with a simple voice command. And while the number of consumers using voice shopping is only about 5%, it is speculated to reach 50% by 2022. A financial digital paper trail will accompany these behaviors, informed by contextual data like time of day, location and parties connected to transactions.

The nature of deeply connected and recorded lives means that personal activity is in constant communication with smart ecosystems that are incrementally surrounding the urban lifestyle of the modern resident.

If you are a Samsung phone user, try saying, “OK Google ” in casual conversation and see if your phone reacts. If it does, the voice-activating feature was set up by default and your phone has been listening to you this whole time.

This functionality of constant audio surveillance – initially intended to inform advertising engines to serve users more targeted advertising – has a real value to the digital forensics community.

Voice Search Means Local search

Once a day, 2 out of 5 adults use voice search. This will no doubt increase the likelihood of unaware perpetrators who grow accustomed to this feature and consequently leave an audio trail of intention in the wake of their crimes.

For examiners and investigators, it is important to note that mobile voice-related searches are three times more likely to be local-based than text-related searches. Being able to access and retrieve this enriched level of digital evidence can be imperative to cases where a suspect’s proximity to a crime, an associate or a piece of evidence is incriminating.

Voice Commands and Other Devices

For other devices such as Google Home or Chromecast, OK Google” features are easily activated, leaving similar opportunities for law enforcement to gain access to data logs and records.

In terms of the variations of initiating voice commands, phones up until now have only recognized “OK Google”, however recently the “Hey Google” command originally reserved for Google Home products to enable the Assistant, has become relevant for some mobile devices.

Ultimately, this voice-first user experience not only allows for creative mobile device unlocking methods but is responsible for merging the digital footprint with the real person. This can lead to a whole new level of investigative certainty when considering identity, intention, and context.

So, as Google’s voice technologies continue to become more and more pervasive and impactful, law enforcement will ramp up its awareness of OK Google and its value as a source of digital evidence.

*Android devices that meet the requirements for the “OK Google” experience need to have Google app version 3.5 or higher, Android 4.4 or higher along with the Voice & Audio Activity setting being turned on, either by the factory preset or manually.

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