The Difference Between Authentication and Authorization

Authentication and authorization are two complementary and critical parts of securing cloud-native applications and infrastructure. Yet, there can be some confusion between these terms. 

The importance of cybersecurity approaches, such as Zero Trust and the principle of least privilege, make it critical to understand and implement appropriate authorization and authentication processes across cloud-native development. 

This article will define authorization and authentication and highlight the differences to help you understand these key elements of security. 

What Is Authentication (AuthN)?

In simple terms, we define authentication — often abbreviated as AuthN — as the process of verifying the identity of users and services  and ensuring that they are who they claim to be. Authentication precedes authorization and is the first step in any security process. 

For users, the following are three main authentication factors — the category of evidence that a user has to provide to prove their identity: 

• Knowledge factor (something you know). The knowledge factor is some data they can provide that the system can check to verify their identity — for example, a username and password or answers to security questions. Providing credentials is the most commonly used form of authentication. 
• Possession factor (something you have). The possession factor requires a user to prove that they possess a physical item, such as a smart card, a phone or a security token. 
• Inherence factor (something you are). The inherence factor involves presenting features unique to the user as evidence. Biometric authentication, such as facial recognition and fingerprint scanning, is an example of the inherence factor. 

Other contextual information like location can also be another authentication factor. For instance, multi-factor authentication (MFA), which requires the user to provide two or more verification factors to gain access to the system, is a better security measure than using a single factor and can prevent credential stuffing and phishing attacks. In 2021, Google saw a 50% decrease in compromised accounts after they auto-enabled 2-step verification for 150 million users. 

What Is Authorization (AuthZ)? 

Authorization, the next phase after authentication, is the process of  defining, enforcing and managing access policies across the cloud-native stack. In modern systems, authorization policies — often policy as code — determine the level of access and user/client privileges regarding any resource. Put simply, it means who or what can do what and in what way.

Some common approaches to authorization include: 

Role-based access control (RBAC)

In RBAC, users are assigned roles according to their responsibilities. Then specific permissions are assigned to these roles that dictate what resources they can access and what users can do with them. 

RBAC is a very popular strategy used in businesses because it is easy to categorize employees based on their job function and place in the corporate hierarchy.  RBAC often has issues with the number of roles defined within an organization, and the governance required to make sure users have appropriate level of access as defined by their roles.

Attribute-based access control (ABAC)

The ABAC authorization strategy introduces a higher level of granularity in access control. Permissions or entitlements are based on attributes or characteristics, and access is granted if all required attributes are present in a subject’s profile. ABAC policies generally offer greater security, because they require more specific conditions about users or services to be met.  

Policy-based access management (PBAM)

PBAM is a modern authorization strategy that uses policy as code to evaluate both roles and policies when granting access. Allowing for context-rich authorization PBAM provides a unified way to manage authorization and allows policy decisions to be decoupled from the underlying application code. 
Open Policy Agent (OPA) is the most popular PBAM policy engine, and uses its high-level declarative policy language, Rego, to implement policy as code across the stack.

Styra Declarative Authorization Service (DAS) is built around modern authorization. We are the creators and maintainers of Open Policy Agent (OPA). This open-source policy engine uses Rego to provide unified policy-as -code across the cloud-native stack. 

Enroll in free courses at Styra Academy to learn more about authorization and writing policies in Rego.

Authenticate vs Authorize: What’s the Difference? 

Here’s a quick rundown on what it means to be authenticated vs authorized: 

	Authentication	Authorization
Function	Verifies clients claimed identity	Dictates what resources the client can and cannot access
Enforcement mechanism	Requires passwords, biometric verification and other authentication factors to work	Requires policies and rules to determine what the resources users can access
Stage in the process	Authentication is the first step in an IAM process	Takes place after the authentication requirements have been met
Visibility to the user	The user can see and change the authentication process to a limited extent	The user can not see or change the authorization rules and policies
In action	Example: After verifying their identity, an employee enters the company’s system	Example: An employee can access resources based on their job function and permissions set by the company. An HR manager can see salary information and vacation time that other employees cannot

AuthN vs authZ in Cloud-Native Computing

The rise of cloud-native application development has brought many advantages, such as better scalability and faster deployment. Gartner estimates that 95% of all digital workloads will be deployed on cloud-native platforms by 2025. 

However, while the IT world quickly developed authentication standards for the cloud-native ecosystem, authorization lagged behind. If you have ever used your Google account to sign into another website, you have used OpenID Connect, an authentication standard that has evolved to provide that best practice for allowing users to use existing authentication accounts to access other services.  

Cloud-native authorization is challenging due to the sheer number of components involved and the dynamic nature of these platforms. Bespoke authorization solutions built into applications using different programming languages often lead to scalability, compliance and security issues. eXtensible Access Control Markup Language (XACML), an early attempt to create an authorization standard, never really gained popularity due to performance issues and the complexity involved.

Simplify Your Cloud-Native Authorization Needs with OPA and Styra DAS

OPA is now considered the de facto authZ standard for cloud-native architecture, providing a unified authorization framework across your entire stack. 

With the Styra DAS control plane, you can easily and quickly deploy OPA across Kubernetes systems, microservices, meshes, API Gateways, public clouds and custom API environments. With its library of built-in policies, development teams can save time and effort and focus on building the application instead. 

FAQs

What are some other authentication standards?

Security Assertion Markup Language (SAML), an authentication standard, is used in most enterprise systems to enable single sign-on (SSO). When a user logs into an internal network, SSO takes the form of a browser session cookie that allows the user to use different applications without having to provide their credentials every time.

What is broken authentication?

Broken authentication is a general term for vulnerabilities and exploits in an authentication system that threat actors can use to force their way into a computer system. Broken authentication often occurs due to poor implementation of authentication and session management.