What are Authentication Protocols – Use Cases and Explanations

Authentication Protocols – Use Cases and Explanations.  In this article we will discuss 5 authentication protocols with their pros and cons and discuss their use cases. Let’s start. 

What is Authentication Protocol

An authentication protocol is defined as a communication protocol for computers designed to authenticate data transfer between two entities. When a user requests the software application, this authentication protocol helps to confirm the digital identification and grants permission to conduct a task by responding to the request. There are several mechanisms (password identification to fingerprints) to authenticate access to a user. These mechanisms add more security and protection to your data against possible threats. Thus, prevent your information from data breaches and create secure communication within computer networks.

Types of Authentication Protocols

To keep your sensitive data safe we recommend to use authentication protocols. This communication protocol ensures that only the intended recipients of that data can access the related information. There are various authentication protocols that one can use to transfer data within computer networks. Let’s explore some of the most common authentication protocols.

Lets find out the Authentication Protocols – Use Cases and Explanations below. 

1. Kerberos

Kerberos is a network authentication protocol that verifies clients/server requests through a cryptographic key. Since Windows 2000, the authentication protocol has been used in many Windows systems and Active Directory (AD) services. Kerberos is compatible with all operating systems, such as Microsoft Windows, FreeBSD, Apple macOS and Linux. The purpose of designing Kerberos was to execute a strong authentication for users requesting access to any application. Licensed under the Massachusetts Institute of Technology (MIT), Kerberos provides authentication and a ticket granting service. Also, the communication network protocol can be used in many mass produced products.

Pros of Kerberos

  • The network authentication protocol is compatible with all operating systems.
  • You can share the cryptographic key of Kerberos much efficiently than public sharing.
  • It is a secure protocol that prevents your data from intrusion attacks.
  • It allows authentication for Web apps.
  • It supports strong encryption and single sign on (SSO) features.
  • The network authentication protocol keeps your data safe from eavesdrops and replay attacks.

Cons of Kerberos

  • Its use is restricted so it can only authenticate clients and services used by Kerberos.
  • It has complex virtual hosting and clusters.
  • Easy to crack a weak password.
  • It requires a central server.
  • It follows a strict time requirement, i.e., the host timings must synchronize within configured limits.
  • Not a standardized administration protocol.

2. Lightweight Directory Access Protocol (LDAP)

LDAP stands for Lightweight Directory Access Protocol, an open and cross platform software protocol developed for AD directory services. This protocol helps locate data and files of any individual, organization, or other devices regardless of the public or corporate network. It is also used as a Directories as a Service to access and maintain distributed directory information services.

Pros of LDAP

  • LDAP is an automated protocol that allows the use of multiple independent directories.
  • It supports existing deployed technologies and directly runs over TCP/IP and SSL.
  • It has a flexible client server architecture.
  • LDAP supports strings to represent data and comprises basic security features.
  • It authenticates best with technical applications, like Docker, OpenVPN, Jenkins or the Atlassian suite.

Cons of LDAP

  • It is hard for LDAP to manage a relational database.
  • You require gateways to use LDAP.
  • The directory servers are a must for LDAP compliance for deployment.

3. OAuth2

OAuth2 is an open standard token based authorization protocol that authenticates limited access to the user on a specific account on the internet. Without exposing the user’s credentials, the protocol enables the third party to access its resources and data. The protocol plays the role of an intermediary with an access token. As a user makes a request to access third party resources, it responds by making an API call and the token is passed with limited access. Many high profile companies, such as Facebook, Twitter, and Google, use this protocol.

  • It is true you can access data without credentials, but at some point, you will need to sign in via a username and password.
  • There are chances of MTM attacks being possible without an SSL / TLS connection.

Pros of OAuth2

  • OAuth2 is a simple and easy to implement authorization protocol.
  • It is easy to share information without releasing any personal credentials to the user.
  • OAuth2 is a cost effective protocol.
  • OAuth2 is more flexible and easier for developers.

Cons of OAuth2


SAML stands for Security Assertion Markup Language, an open standard protocol that uses XML based authentication data format to transfer information between two parties (identity provider and service provider). The introduction of SAML simplified the authentication process. It allows users to access multiple applications across a domain.

Pros of SAML

  • SAML authentication provides a single sign in for accessing multiple web applications.
  • It provides a secure method to allow user authentication.
  • The administrative cost for end users is also reduced.
  • It provides enhanced security by allowing a single point of authentication.
  • You no longer need to maintain or synchronize user information between directories.

Cons of SAML

  • You need an Identity provider for smooth functioning.
  • A single XML format manages all your information.


RADIUS stands for Remote Authentication Dial In User Service, a client server protocol that provides users a centralized Authentication, Accounting and Authorization management. The protocol runs in the application layer and comes into function when a dial in user requests access to a network resource. The role of the RADIUS authentication protocol is to encrypt the user’s credentials and map via the local database to provide access. It is now mostly used for remote access across numerous networks.

Pros of RADIUS

  • It allows multiple users to access resources via the RADIUS Authentication protocol.
  • During a session, it assigns a unique identity to every user. Thus, it reduces the threat of hackers.
  • No issue with password management as each user saves and manages their own.

Cons of RADIUS

  • Implementation at the initial stage is difficult on hardware.
  • The RADIUS authentication protocol is costly as you need to invest in experts for numerous models.
  • Maintenance and management of on prem hardware can become more intensive and frustrating later.

Authentication Protocols – Use Cases and Explanations

1. IoT Device and Relevant Applications

In this use case, IoT devices such as Amazon Alexa use a digital identity to control access to the app or its cloud resources. These devices are connected to the internet via an IP network. Thus, you need to create an account first and then transfer information from the data store. In this case, OAuth2 is the preferred authentication protocol to allow access to resources. Also, the protocol is simpler to use with smart devices without keyboards or screens.

2. A Consumer Identity Provider (IDP)

Let’s consider an online bank service provider or a government service that wants to transfer identity data to other relying parties (RPs). In this case, the identity provider (IdP) manages KYC (know your customer), approves and verifies sensitive data and the user’s attributes. Thus, the IdP holds identities assured to a standard level and only the authenticated RPs can access them.

So here, when you require strong security, you must choose SAML authentication. Security Assertion Markup Language is an open standard protocol that will allow an exchange between the RP and IdP. To ensure each party is communicating with the correct user, it requires both parties to digitally sign and validate the user. Also, the IdP uses encrypted keys that are often rotated for safety reasons. Thus, the HTTPS feature is not the only security provided by SAML to protect against attackers. These features add double protection to users’ data.

3. Automation server

LDAP is good with authenticating Linux based applications and is used in various automation servers, such as Jenkins, Atlassian Jira & Confluence, Kubernetes, Docker. It is a versatile protocol that can be used to integrate thousands of applications. LDAP’s lightweight, adaptive and foundational features allow easy management of open source Linux clusters. It allows users to easily connect with systems, applications, files and networks regardless of the platform or location.

What are Authentication Protocols – Use Cases and Explanations Conclusion

Authentication protocols are designed to keep your sensitive data safe from imposters and hackers. Today, there are many people who excel in stealing identity on a network. For instance, if a user gets access to any device or its configuration file, they can easily crack password and transfer all your sensitive data. Thus, these network authentication protocol keep your information safe when transferring data or accessing another device. They help confirm the identity of a user on request access to a network resource. Kerberos, Lightweight Directory Access Protocol (LDAP), OAuth2, SAML, Remote Authentication Dial In User Service (RADIUS) are a few authentication protocols.

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

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