Authentication vs Authorization: What's the Difference?

Cybersecurity is essential for businesses today to protect company systems, information and resources from hacks and threats and to keep customers' data safe. In the case of online customer accounts, access must be carefully controlled. And to do this, businesses need certain security measures to authenticate and authorize users.

If you're wondering what is the difference between authentication vs authorization, you're in the right place. Read on to learn about each process and how they vary.

What is authentication?

Authentication (aka verification) means checking that something is true or correct. In a business context, authentication is about checking that an account or app user is genuine and granting access to systems only once that person's identity has been confirmed. There are several types of authentication methods – we explain the most common ones below.

Typical user authentication process and types

All methods involve matching security credentials with either pre-set values or values generated by a system at the time when a user attempts to log in or gain access.

1. Password-based authentication

The simplest (and least effective) authentication method is where users enter a single password to log in to their accounts. This is known as single-factor or single-sign-on authentication. Cybercriminals love this method as it's not very secure – passwords often get exposed or are easy to hack.

2. SMS verification

SMS verification is a two-step process. First, the user attempts to log in online with their password. Then they're sent a PIN code via a text message to their mobile phone. The user must enter that exact code online to verify their identity and complete the login process. SMS authentication is deemed secure because it relies on the user having access not just to their password, but also a unique access token delivered to their device.

3. Time-based one-time password (TOTP) authentication

TOTP authentication is another two-factor method, commonly used with third-party authenticator apps. The user begins the login process online and then must open an app on their phone to receive a time-sensitive, unique security code. The access tokens are generated with the current time as an input and expire after 30 seconds or so, meaning the user has a very short window to enter the code online.

4. Biometric authentication

This method relies on distinctive biological characteristics to verify (beyond doubt) that a user is who they say they are. Examples are facial recognition, retina scanning and fingerprint matching. Authentication works by comparing a user's physical characteristics to a stored set of biometric data.

5. Physical key

As the name suggests, this option involves a physical security key that provides a backup to a password – it works similarly to two-factor authentication. An example is the Google Titan Security Key, which looks and acts like a USB stick. Others are available for mobile devices, and some also connect wirelessly. The onus is on the user to protect themselves with hardware keys.

6. Multifactor authentication

Multifactor authentication is where more than two authentication factors are used to verify a person's identity. Users could be asked to enter a password, provide a unique PIN code and also answer a security question or scan their fingerprint. Multiple authentication factors combined deliver the highest level of security.

What is authorization?

Authorization is the process of granting user permission to access an account or resource. Authentication comes first – users must prove they're genuine before authorization can happen.

Common types of authorization

Role-based access control

Role-based access control (RBAC) involves setting different permission levels according to user roles. Many organizations use RBAC to ensure employees can access only the information needed to perform their jobs effectively.

If you have a Facebook business page, you'll notice you can assign different roles (and permissions) to team members. Administrators have full control over everything, while Moderators have limited permissions (they can't manage page roles, edit the page or add apps).

Rule-based access control

Sometimes abbreviated as RuBAC, rule-based access control manages access according to a set of predetermined rules instead of a user's role. The person who sets access rules is the system administrator, and users must exhibit their access credentials to a control mechanism to gain (or be denied) access.

Firewall software is one example that uses RuBAC. It guards network access by filtering web traffic according to IP address, individual ports and other criteria.

Attribute-based access control (ABAC)

Attribute-based access control, or ABAC, grants access to users based on assigned attributes. So in a business, employee permissions could be based on location, department, job type, etc. If someone is promoted from coordinator to manager, their access permissions will be updated according to the change in business attributes.

Authentication vs authorization: an in-depth comparison

As we've suggested, there are several differences between authentication and authorization; we explain the main factors below.

Purpose or focus

The purposes of authentication and authorization are completely different. Authentication is where a user verifies their identity to obtain access to an account, app or resource. Whereas authorization determines what users are allowed to do and then either grants or denies access.

Process

The authentication process is visible to the user. For instance, they can change their privacy settings and carry out a password reset. Authorization is invisible to the user – permissions can't be changed, upgraded or removed by them – only an administrator can do this through one of the access control methods mentioned earlier.

User experience

Authentication is user-friendly, so even people with limited technical knowledge can understand what to do to gain access to a system. Instructions are displayed on login pages or popups for users to follow. But authorization policies and processes are much more technical. Fortunately, users don't need to know the ins and outs of the authorization process; it all happens seamlessly in the background.

Order of operations

A user is first authenticated and then authorized (it can't happen the other way around). The systems, resources, or data that a particular user can access are determined only after they've been successfully granted entry using the correct credentials or by being matched to predetermined criteria.

Scope

Authentication is typically performed once to verify the user's identity at the start of a session or transaction. However, authorization may be performed multiple times during an interaction to ensure the user is permitted to access each resource they request, such as different parts of a website, app or program.

Scale

Authentication is considered more top-level, with authorization lower level. This is because the latter is complicated and does much more than simply granting entry to a user. There are a lot of layers to authorization, and therefore, lots of places for things to go wrong.

Costs

It isn't easy to compare prices for authentication and authorization as several factors come into play, starting with what level of security your business needs. In any case, both are necessary expenses.

The cost of 2FA or multifactor authentication depends on whether you build and maintain a system in-house or deploy a ready-made API software solution. The latter is more cost-effective but may give you less control over specific functionality.

With authorization, you must first decide what model to use and then add it to your application. The cost depends on whether you build the solution in-house, hire experts, use a third-party service or use open-source libraries to handle the process.

Importance and risks

Authentication and authorization are both essential for protecting customer data and business systems.

The failure of these processes can have a significant detrimental effect. For example, if authentication fails and users can't access your product/services, this will cause frustration and possibly result in customers going elsewhere. And a single slip-up on the authorization side may mean data is exposed, leading to a loss of trust and a PR disaster.

Authentication vs authorization: explained