Authentication vs. authorization: What's the difference?

What is authentication?

Authentication is a process that verifies an individual's or device's identity. The primary goal is to confirm that the entity presenting valid credentials is genuinely who it claims to be. Users submit the required security token to confirm their identity, which is checked against a database of authenticated users.

User authentication is crucial because it’s often the first defense against data breaches and cyberattacks. Authentication systems have multiple ways to verify user identity, usually implementing approaches like multi-factor authentication (MFA) or two-factor authentication (2FA).

A user can submit three types of security tokens for authentication:

• Something they know. Access tokens like a username or password that only the user would know. Personally identifiable information (PII) can also be used, particularly on platforms like social media sites.
• Something they have. A physical access token, such as a keycard, security badge, or USB key, can also be used to authenticate the user's identity. These tokens are typically used in environments that require a high level of security.
• Something they are. Stricter authentication techniques can use facial recognition, biometric authentication, and other unique identifiers tied to a user’s physical characteristics. This method is typically employed to secure highly sensitive systems or restricted locations.

What is authorization?

Authorization is a process that determines an authenticated user's permissions once they access a system. Authorization is necessary because systems typically require multiple levels of access. Different users require varying levels of privileges to perform their roles effectively or access specific resources and locations. 

The primary purpose of authorization is to limit access to users based on their allowed permissions. For example, a company’s HR system may use role-based permissions. It may authorize employees to access only their personal files while allowing managers to view their team’s performance data. 

Access control in authorization systems is usually overseen by authentication providers (such as a company's IT or security team), who grant permissions as part of an organization’s overall security strategy.

Aside from controlling access, authorization systems are crucial in helping system or site administrators maintain a more accurate overview of how individuals use their access privileges. This capability is essential for creating additional security protocols like access logs to track which users access confidential data.

What's the difference between authentication and authorization?

The primary difference between authentication and authorization is that authentication verifies the user's identity to grant access, while authorization determines the user's access levels. Authentication decides whether a user can enter a system, while authorization controls what a user can do once inside the system.

Authentication and authorization are always interlinked. It's never a good idea to stop at just user authentication since different users require varying permission levels, especially for areas or systems holding sensitive information.

Understanding the distinction between the two is important because each system is vulnerable to different types of threats. Recognizing their differences is one of the most effective ways to mitigate security risks.

What comes first?

Authentication will always come before authorization. A security system assumes that administrators have already verified the identities of users authorized to access specific areas or data. Once authenticated, users access the specified resources by presenting the correct credentials.

Which process is more straightforward?

Authentication is more straightforward because several methods (such as multi-factor authentication) can quickly verify a user’s identity. Administrators must authorize users manually to ensure they only gain access to what they're allowed to see.

What kind of protocols do they follow?

Authentication protocols follow the OpenID Connect (OIDC) standard, which allows for single sign-on sessions and standardizes the way users gain access to systems. Authorization protocols commonly use the OAuth 2.0 protocol, which supports OIDC to give users access to multiple systems and applications with a single authenticated request.

Authentication vs. authorization in API

Now that you better understand the differences between authentication and authorization, what are the concrete examples where these concepts apply? Beyond allowing physical access to restricted areas, the most well-known example of authentication and authorization protocols is how they enable access to digital systems.

Implementing authentication and authorization protocols into the API (application programming interface) allows for secure access to digital resources. 

Authentication in API

API authentication usually grants access using API keys, OAuth tokens, HTTP basic authentication, or a JSON Web Token. Users access the system once the API checker ensures the submitted credentials match the information stored in its database.

API authentication is crucial for ensuring that only verified users are given secure access to the system, protecting against unauthorized access. The various authentication methods allow for flexibility, enabling organizations to balance user convenience and robust security protocols.

Authorization in API

API authorization checks an authenticated user's access permissions, ensuring they can execute the desired actions within the application or system without gaining access to resources or functions they shouldn't be using.

While API keys and JSON Web Tokens can be used for authorization, most authorization systems today use protocols like OAuth 2.0 to allow users a wider range of access without compromising security. API authorization has its own security environment but still relies on robust API authentication to work effectively.

Ensure secure access with authentication and authorization

Authentication and authorization are fundamental components of most security systems. Understanding the differences between the two allows you to address their specific vulnerabilities and reduce security risks, ensuring secure access for users. This knowledge also enables you to strengthen and expand your security systems for a more comprehensive suite of protections.