What is Authentication?

Table of Contents

Authentication is the process of verifying that a person, organization, service, or application has permission to access a system or resource. The authentication process is meant to answer the question of, “Is the person or entity attempting to access this resource who they say they are?”

Authentication's primary purpose is access control and to ensure that only authorized users can access specific systems or resources. Strong authentication policies are vital for safeguarding sensitive data and information and for preventing security breaches.

Authentication can be done using different methods by the verifying party (the person or entity that is granting access). These methods include verifying firsthand knowledge of the outside party, comparing attributes based on what is known barring direct knowledge, or using documentation to support the claims.

When authenticating users to an online service, direct knowledge is unrealistic, so the best efforts are taken to verify that the credentials a person has are the ones given by the system administrators. Hence, authentication to online services is not always foolproof.

Authentication's primary purpose is to provide controlled access to systems, applications, websites, databases, or other resources. It helps to maintain the privacy of personal information or data, and reduces the risk associated with accessing resources digitally. Some of the major benefits of strong authentication policies include:

Controlling access to systems, applications, or other resources
Maintaining the confidentiality and privacy of sensitive information or data
Enabling convenient access to systems or resources digitally
Limiting the impact of compromised credentials
Satisfying compliance or regulatory requirements
Creating an audit trail to support governance, compliance, and security investigations

To authenticate a person, the service verifies a user who is required to present one or more authentication factors:

Knowledge factors, or something the user knows
Possession factors, or something the user has
Inherence factors, something the user is or something that is unique to the user
Location factors, or validating that a user is in an authorized region, workplace, or facility

Strong authentication is authentication with more than one layer, or factor, of authentication. By definition, strong authentication systems include two-factor authentication (2FA) or multi-factor authentication (MFA).

There are a wide range of authentication methods in use today with varying degrees of security risks and convenience for the verifying user. Some of the most common authentication mechanisms include:

Usernames or passwords
Magic links
Token-based authentication
Social logins
Push notifications or authenticator apps
One-time passwords (OTPs)
Passkeys
Card authentication (smart cards, keyfobs, or badges)
Biometric authentication (facial recognition, fingerprint, voice recognition, etc.)
Certificate-based authentication
Passwordless authentication

Each method has its own strengths and weaknesses, and organizations often use a combination of these methods depending on the level of security required for particular systems or resources. For more information about the different ways to authenticate, check out our guide on the different authentication methods.

As we mentioned above, authentication is not entirely foolproof. Security can vary significantly depending on the authentication methods and number of factors in use, and the authentication process can create user experience friction which may lead to inconsistent adoption.

HYPR’s 2025 State of Passwordless Identity Assurance Report surveyed 750 global IT and security leaders. The report found that nearly half of organizations experienced a security incident, and 87% of those incidents were directly related to identity vulnerabilities. With so many incidents tied to identity verification and authentication, it’s important to understand the common attack vectors for identity security and which authentication methods are the most secure.

The National Institute of Standards and Technology (NIST) has a list of common authenticator threats, which are summarized in the table below:

Authenticator Threat/Attack	Description
Assertion Manufacture or Modification	The attacker generates a false assertion or modifies an existing assertion.
Theft	A physical authenticator key or device is stolen by an attacker.
Duplication	The user’s authenticator has been copied with or without their knowledge.
Eavesdropping	The authenticator secret or value is revealed to the attacker as the subscriber is authenticating, or is intercepted via a compromised communication channel.
Offline Cracking	The authenticator is exposed using methods outside of the organization’s live authentication environment.
Authentication Fatigue	An attacker creates repeated authentication requests for the subscriber in an effort to trick them into approving.
Side Channel Attack	The authenticator secret is exposed using physical characteristics of the authenticator.
Phishing or Pharming	The attacker tricks a target into revealing authenticator output through a counterfeit link, verifier or CSP.
Social Engineering	The attacker establishes trust with a target to trick them into revealing an authenticator or authenticator output.
Online Guessing	The attacker attempts to guess a valid authenticator output based on accessible online information about the user.
Endpoint Compromise	Malicious software compromises an endpoint used for authentication.
Unauthorized Binding	An attacker causes an authenticator under their control to be bound to a subscriber account.
Latent Keys	A decommissioned device retains authentication keys.
Key Transfer Security	Authentication keys are transferred between devices through an insufficiently secure cloud service.
Untrusted Devices	Authentication keys are used on a device that provides insufficient protection.
Insider Threats	A trusted user intentionally or unintentionally exposes an authenticator.

Authentication is one of the pillars of the Identity and Access Management (IAM) process and is essential to validate the identity of a user on an ongoing basis. At a broad level, the IAM process entails:

1. Identity Verification (Who are you?)
Identify verification confirms someone is who they claim to be in order to establish a digital identity (which may include user accounts, attributes, roles, or system privileges). This process creates the identity record that authentication will later confirm.

2. Authentication (Can you prove it?)
Authentication is the mechanism that confirms a claimed identity when attempting to access a resource. Without authentication, the verifying party has no way to trust that the person presenting credentials is the legitimate identity holder.

3. Authorization (What level of access?)
Once identity is confirmed via authentication, the authorization process enforces what resources and actions that identity is permitted. Authentication is a prerequisite — authorization decisions are meaningless if you don't know who is asking.

4. Access Management (Managing the above)
The organization controlling the IAM process is responsible for provisioning, deprovisioning, and governing identities and their access rights over time.

Authentication is at the heart of IAM - it helps to bridge the gap between identity verification and authorization by ensuring that the access request has been sent by the legitimate owner of an account or resource.

Authentication and identity verification are closely related and both are meant to prove that someone is who they claim to be. However, the two processes have a layered relationship:

Identity verification is the initial process of proving that a real person exists and is genuinely who they claim to be. This is typically a one-time or infrequent process that establishes a ground truth. Examples include checking a government-issued ID or performing a biometric scan.

Authentication is the ongoing process of confirming that the person currently accessing a system or resource is the same person whose identity was previously verified. It relies on credentials or factors established during the identity verification process.

Put another way:

Identity verification asks: "Are you really Jane Doe?" (establishes the identity)
Authentication asks: "Are you the Jane Doe we already verified?" (confirms identity at access time)

You can learn more about the overlap and differences between identity verification and authentication here.

Authentication attacks aiming to defraud, steal data, or upload malware are among the most common cyberattacks. One of the biggest reasons for this is the relative weakness of many forms of authentication, especially when it comes to simple passwords or other single-factor authentication approaches.

HYPR’s passwordless MFA solution not only offers top-of-the-line security, but it helps eliminates user friction from the login process so organizations don't have to compromise between security assurance and user experience. HYPR is FIDO-Certified from end to end and easily integrates with all major identity providers and SSO tools.

For more guides on authentication methods, implementation tips and related concepts, check out our authentication resource library here.

Authentication 101: What it is and How it Works

Why is Authentication Necessary?

The Four Authentication Factors

Common Methods of Authentication

Authentication Threats and Common Vulnerabilities

How Does Authentication Fit Into Identity and Access Management (IAM)?

How Does Authentication Relate to Identity Verification?

How HYPR Supports Authentication

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