LibraryblogWhat is Authentication? - A Complete Guide

What is Authentication? - A Complete Guide

We delve into authentication - what it is, the different methods you encounter daily, and why it's crucial to the security of so many online businesses.

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Ucha Vekua
May 25, 2021
Blog Post
ID Verification

Simply put, authentication is the procedure of recognizing a user's identity. It runs at the start of an application and validates users to make sure that they fulfil every security requirement.

Different systems require different credentials to confirm an identity. This credential is often a password, but it can also be other forms of authentication, depending on the service and security features that the application needs to have. There are two main phases for the whole procedure - identification and actual authentication, which makes sure that everything is secure and the user has access to the right tools.

In this article, we'll dive deep into this topic and talk about different forms of authentication, technologies, techniques and help you understand why it is essential for your business to have a proper authentication system.

Types of authentication

There are many different methods of authentication and technical types of authentication . Cyber attacks are improving over time, and security teams need to be ready for new challenges. They look to implement more sophisticated systems to secure their users and make sure that safety is guaranteed. And this is why there are so many types of authentication available, as they try to cover a variety of requirements. The most common authentication types are:

Single Factor/Primary Authentication

The simplest way to secure your access to a system. In this case, you need to match only one credential to verify yourself online. This is most often a password, the most popular form of authentication.

Two-Factor Authentication (2FA)

Two-factor authentication provides an extra layer of security, and is a common authentication method. It ensures that a system is safer for its users. After entering your username and password, you need to complete an additional step and provide another piece of information, which can be a PIN, an answer to a “secret question”, a number sent by SMS/email, or even your biometric features (using Face ID or Touch ID for example). These additional steps are what make this type a two-factor authentication method.

Single Sign-on (SSO)

SSO lets you securely authenticate yourself with multiple online accounts by using only one set of credentials. It's really any time you have the option to log in using Google, Apple, Facebook, or another provider. This system is based on a digital certificate that the service provider and identity provider have exchanged. The identity provider sends the identity information to a service provider through this certificate to know that it is coming from a trusted source.

Multi-Factor Authentication (MFA)

With multi-factor authentication, you're required to provide two or more verification and authentication factors to access the system. The system can be an application, online account, or a VPN. This authentication method is the main component of a strong identity and access management policy. Using MFA for your systems will decrease the chances of a successful cyberattack.

Password Authentication Protocol (PAP)

A clear-text authentication scheme, which uses a two-way handshake to provide the system with a method for establishing an identity. In this case, the information is not encrypted, which is why this form of authentication is not secure from a cyber attack.

Challenge Handshake Authentication Protocol (CHAP)

CHAP is an identity verification protocol that periodically re-authenticates the user during an online session. Unlike PAP, this protocol is secure and attack resistant. In order to authenticate, the authenticator has to send a message to a party that requests access.

Extensible Authentication Protocol (EAP)

Finally, EAP can support multiple authentication mechanisms - currently, there are around 40 different methods available. EAP is a framework mostly used in point-to-point connections and wireless networks. It is not a specific authentication mechanism.

What is an authentication error?

It is common among users to receive an ‘authentication error' notification when they try to either set up Wifi, make an API request, or simply register somewhere. This means that the device cannot authenticate the system because of some specific reason, which can be a recent device update, unstable network connection, or server overload. In this case, there is always a way to configure details and solve problems from the authentication method itself, but it heavily depends on the problem.

Authentication technologies and software

There are quite a few innovative technologies available that help us secure systems and authenticate people using different methods. Leading authentication technologies include facial recognition software, smart cards, authentication as a service, and more. Here are the four main types of these technologies that make our everyday lives easier:

  • Password-based authentication technologies Biometric-based
  • Certificate-based authentication technologies
  • E-token based authentication technologies 

Methods of authenticating people have progressed over time. A couple of years ago, it was primarily passwords. But now, we see more and more options and technologies across the board. This market moves fast, and technologies need to adapt to the new reality. This is the drive behind the different emerging options and techniques to secure our online systems.

Authentication techniques

Lately, authentication has become one of the most common processes in the world of mobile apps and web development. It is important to know about different techniques for authenticating users and authorizing them to grant access to particular software. The most common types of authentication techniques are:

  • Token-based authentication
  • Session-based authentication
  • Cookie-based authentication
  • Claims-based authentication
  • Digest authentication

Each of these techniques have their own purpose and use case. It all depends on the type of service you are offering to users and the security layers you need for protecting yourself and your customers.

The principles and the importance of authentication

Controlling access and letting the right people in is essential for a successful online security system. You can ensure this by using various authentication methods to check if the person seeking access is authorized to enter or not. It is typically the main element to secure your system easily.

The procedure is pretty simple. In order to access a system, the user needs to enter their UserID and a secret password. But this process has its own risks - it does not really authenticate the individual person. It might be that a criminal acquires this information, letting them access the system. So, this method authenticates a device regardless of who is behind the screen. This is why there are so many different authentication methods available. Businesses can implement the ones they need depending on the nature of what they do and the security features they need to have. The purpose of authentication is to make sure that the right people are accessing systems.

Authentication vs Authorization

Authorization might sound similar to authentication, but in reality, they are very different security processes. Authentication makes sure that users are who they claim to be. But, authorization gives those users access to a specific resource or function.

Let's try to understand the relationship between these two with a simple example. If you own a restaurant, authentication helps you give your staff members access to the workplace areas if they provide the right credentials to your systems. And authorization gives them permission to access specific places and data they need to do their jobs successfully. Both of these systems help you to be more secure but their purpose is different.


To sum it up, authentication is an essential part of our online security and everyday life. It helps us make sure that our accounts are secure from cyberattacks with the help of many different effective methods available.

Here at Veriff, we work hard to build trust online and make the digital world safer with the tools we are building daily. That's why we recently launched Face Match , our innovative authentication and reverification method, to make sure our clients can keep their users safe. And if you're wondering "Why Veriff?", why not take a look at our comparisons with Onfido Jumio to see why our clients choose us.