Voice Authentication: How It Works & Is It Secure?

Voice authentication makes logins as easy as speaking. This may sound futuristic, but it’s the security that’s saving businesses from breaches every day.

Is voice recognition secure? Yes, voice recognition is secure, especially when compared to classic logins that require a username and password. Similar to other biometrics, voice recognition is more secure because a person must interact with a login rather than simply enter a code.

What is Voice Authentication and How Does it Work?

Voice authentication is a form of biometric authentication. “Biometrics” is a specific term that describes the use of unique physical markers like fingerprints, facial features, or even someone’s iris as a form of authentication for users.

Voice recognition is a form of biometrics, and voice authentication is the use of a user’s speech to authenticate users. Like fingerprints and facial scans, voice and user speech can serve as a unique marker of a user’s ID. This fact means that voice authentication carries many of the same advantages of other biometrics, including:

  1. Harder to fake than other forms of authentication. A password can be stolen, and a token can be copied or forged if security isn’t kept tight. Biometric data is much harder to fake, all things being equal, and it is much harder to steal through practices like broad phishing attacks.
  2. Supports streamlined user experience. Logging into a system shouldn’t be difficult, regardless of whether or not it’s one of your employees or one of your clients or customers. With biometrics, secure authentication methods can rely on the person just being there, rather than remembering a complex password.
  3. Accessible and convenient on a variety of devices. Biometrics are becoming incredibly common on devices like laptops, tablets or smartphones. That makes it that much easier to integrate next-level security across a productive device ecosystem for distributed teams.
  4. Contactless login. This is something unique to speech recognition (among a few other biometrics like facial scanning). With speech recognition, you don’t have to touch anything–which, as we’ve learned from the pandemic, is a safe and responsible step to take.

Speech recognition works by breaking down recordings into segments of frequencies and uses those frequencies to create a unique “fingerprint” to identify different tones and inflections in a user’s voice, which can then serve as an artifact for identity verification. Typically, the user will repeat a phrase or collection of phrases to “train” the recognition software to recognize unique vocal qualities based on two qualities:

  1. Physiological qualities: These include things like tone, pitch and volume.
  2. Behavioral qualities: unique inflections in speech that come from accents, regional dialects or idiosyncrasies.

These are often features of our speech that we don’t even notice in our daily lives–but, learning algorithms can pick them up and sift through different types of speech at the level of wavelength and frequency to construct unique vocal patterns.
While AI and biometrics have evolved over time, that doesn’t necessarily mean that voice is foolproof. There are several disadvantages, some that are shared by other biometrics and some unique to voice technology.

Voice authentication is:

  1. Hackable. When your system stores vocal data, it does so the same way it does other data: in a server or database. If that point isn’t secured, then hackers can steal the data and use it to build fake recordings that match.
  2. Non-replaceable: If biometrics are compromised, it cannot be replaced like a password because you can’t simply change your voice.
  3. Not 100% accurate. No authentication method is foolproof. This is just as true for speech recognition. However, industry innovation in AI and anti-spoofing have made biometrics viable for even secure applications like payment processing. However, it’s important not to rely on a single form of identification.
  4. Not as applicable in all environments. Speech recognition requires a rather silent area. Audio artifacts outside of the user’s voice can interfere with authentication, which can cause problems if you are using voice alone.

Risks of Voice Authentication

While there are some disadvantages, some of these disadvantages can turn quickly into security risks or limitations against user experience. These include things like:

  1. Voice changes can impact access. Users who relied on face recognition to unlock their phones quickly learned during the pandemic (and required mask-wearing) how relying on a single method can limit access. A loud environment can impact authentication, but so can normal incidents be including colds, sore throats or more minor changes in voice, accent or speech patterns.
  2. Technical vocal disguise. New tools can modulate voices to sound like other voices, and in some cases, these can fool biometrics. There is a consistent back and forth as these security systems stay ahead of these technologies, as voice deep fakes are becoming more common.
  3. Liveness Detection. Because voice technology is somewhat easier to spoof than other biometrics, it does call for liveness tests to verify it’s an actual user present and not a spoofing machine.

What is Liveness Detection?

Liveness detection is a practice that exists specifically to fight spoofed biometric data. That is, to determine when a biometric piece of information is from a live person rather than a machine or algorithm (deep fakes or fake fingerprints, for example), it’s often necessary to use a liveness test.

In simplest terms, liveness is a method of programming user recognition that can detect whether or not a biometric piece of data is from a human rather than a bot. For example, these tests are meant to determine whether or not things like sound artifacts were actually spoken and not just from a file. In terms of biometrics and voice spoofing, researchers are learning how to develop deep learning solutions to address common deep fakes and spoofs.

The Costs of Effective Voice Authentication

In terms of compliance, security and privacy, it’s important to understand the value that biometrics can bring to your organization as a weight against direct costs.
Consider the following:

  1. Voice biometrics can function as part of Multi-Factor Authentication (MFA) to reduce IAM problems while easing user experience. Passwords can often be unwieldy and easily lost or forgotten. A voice system can leverage passwords as part of an MFA schema or a biometric password itself.
  2. Voice biometrics can reduce fraud and breaches. Voice, included with other security measures, can provide additional layers of security that prevent compromised data due to breaches, password hacks, phishing attacks and any additional threats.
  3. Voice biometrics are easy to implement in various devices and cut down on lost credentials like passwords.

Depending on the implementation, a voice recognition system can also be relatively inexpensive on top of the benefits it provides.

Passwordless Authentication with Voice Biometrics Using BlockID

Voice authentication is a useful, if emerging, IAM technology. Its strength lies in how it works with other tools to provide high-level security. That’s why 1Kosmos includes voice biometrics as an authentication option–alongside fingerprints and face scans–for its BlockID passwordless authentication.
We accomplish this through a combination of innovative techniques and technologies:

  • Identity Proofing: BlockID includes Identity Assurance Level 3 (NIST 800-63A IAL3) detects fraudulent or duplicate identities and establishes or reestablishes credential verification.
  • Spoof-Resistant Liveness Testing: Our liveness testing algorithms help your system resist faked credentials by enforcing the presence of a user to properly authenticate system entry.
  • Identity-Based Authentication Orchestration: We push biometrics into a new paradigm of “who you are”. That is, BlockID uses biometrics to identify individuals, not devices, through identity credential triangulation and validation.
  • Integration with MFA: BlockID readily integrates with standard-based API to operating systems, applications and MFA infrastructure at AAL2.
  • Cloud-Native Architecture: Flexible and scalable cloud architecture makes it simple to build applications using our standard API, which includes utilizing private blockchains.
  • Privacy by Design: 1Kosmos protects PII in a private blockchain and encrypts digital identities in secure enclaves only accessible through advanced biometric verification.

Learn more about 1Kosmos Passwordless Enterprise authentication. Also remember to sign up for our newsletter to stay abreast of 1Kosmos products, events and updates.

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Meet the Author

Rohan Pinto

Co-founder of 1Kosmos

Rohan is the co-founder of 1Kosmos. He is a go-to security and identity management expert and the founder of several businesses that have made considerable advancements in blockchain and identity management.