From open banking APIs to security APIs, these solutions are driving modern web-way of communication, enabling them to communicate with each other. And that’s why you API security is becoming a growing concern.

The issue is real.

More than  41% of companies suffer from API security incidents in past years. Thus, leading to 286% increase in API centered attacks.

Companies are investing millions in API security. In fact, more than 91% of developer believes that API security should be a priority.

So, if you are planning to integrate API in your solution or want to learn how you can secure API, this blog is for you.

API: What is API Security?

API or Application Programming Interfaces are set of instructions that allow apps to communicate with each other and conduct the transfer of data. As such, APIs are a fundamental part of microservices architecture i.e. majority of modern software.

Now that you know what is API, let’s see what exactly “API security” is:

The term API Security refers to the process of securing APIs against cyber-attacks.  Well, API is the bridge that allows two software or programs to communicate with each other. And exchanging crucial information, they are point hackers attack first.

Though API security has a big role to play in modern software security, it also has it’s differences. So, before we discuss API security’s importance, let’s look at general app security and API security.

App Security vs API Security: The Difference

General App SecurityAPI Security
Focuses on protecting the overall application from a wide range of threatsFocuses on securing the APIs that allow different software applications to communicate with each other
Includes implementing secure coding practices, encryption of sensitive data, authentication and access control mechanisms, and regular security audits and testingIncludes implementing access controls to limit who can access the API, using authentication and authorization mechanisms to ensure that only authorized users can use the API, implementing rate limiting to prevent overuse of the API, and encrypting data that is transmitted over the API
Protects against unauthorized access, data breaches, and malicious attacksSpecifically focuses on the unique risks posed by API usage
Important for protecting software systems from various security threatsNecessary for securing the interactions between different software applications
This applies to the overall application and its componentsThis applies specifically to the APIs and their usage
Helps ensure the confidentiality, integrity, and availability of the applicationHelps ensure the confidentiality, integrity, and availability of the APIs and the data transmitted over them

With this out of the way, let’s look at why API security is important.

Why is API Security Important?

Why is API security important?

Well, as we discussed APIs are responsible for transferring important data. For instance, Open Banking API allows fintech apps like eWallet to access a person’s bank data.

So, in case anyone manages to hack, expose, or compromise API, it can mean a leak of personal data, financial data, and any other data of sensitive nature. This is something that neither business nor a user wants. And it can end up in loss of billions as we see every year.

Therefore, securing API is of immense importance.

With software and app development growing popular, the use of API is also growing very common.  In addition to this, the number of cyber attacks is also increasing.

For that reason, securing API is more important than ever.

Speaking of which, let’s look at two types of API architectural styles and what are the differences between them.

REST API Security vs SOAP Security

People often ask, what are the types of API security? And the answer to it is 2.

Well, these are SOAP and REST.

SOAP API refers to a well-structured message protocol that allows multiple low-level protocols.

On the other hand, REST API is a simpler one that uses HTTP/S in the form of the transport protocol. As such, this one uses JSON format for the purpose of transferring data.

SOAP API securityREST API security
Offers protocol extensionThere are no built-in security capacities
Based on W3C and OASIS including SAML tokens, XML encryption, and XML signaturesREST API security must be integrated with data transmission, deployment, and interaction.
Built In Error Handing Via WS reliable messaging support.No Built-In Error Handling.
Support Web Services Specifications. Allows extensions like WS security.Deployed with API gateway for better security.


API Security management


API Security Management

A big part of API security is API Security Management. So, in order to do this and secure API, the majority of the platforms allow three major times of API security schemes.

These are, as mentioned below:

  • An API Key – This security scheme uses a single token string. For those who aren’t familiar with the term, it is hardware that enables unique authentication information.
  • App ID/App Key – this is a two-token string method that is often seen in the form of a username and password-based authentication.
  • OIDC/ OpenID connect – this method creates an identity layer based on OAuth Framework. It is used to identify users via their profile information and authentication server.


API Endpoints

One can’t finish the API security discussion without talking about API endpoints.

These are points of contact and communication between two APIs. In more technical terms, they are URLS and digital locations on which APIs send data and receive.

API Endpoints are highly important as they are the exact location of data exchange. If this doesn’t function properly, the API will stop working.


Well, you might be wondering why the security of web API or mobile app API is important at all. Let’s look at some of the top examples of API security breaches in the next section.

API Security Breaches Examples

API Security Breaches

Do businesses often wonder whether investing in API security is really worth it? Well, it is as important as business app development.

In fact, there are various examples of large companies losing billions and tons of sensitive data due to their API security breach.

So, let’s look at some of the important examples.

2017 – Equifax API Breach

Some 6 years ago, Equifax, a credit reporting agency saw a huge data breach over its API. Hackers got access to the sensitive data of over 143 Million people.

2018 – Strava API Breach

Strava is a popular fitness mobile app. Well, as it turns out, it was ( is ) used by a number of US military personnel to track their activity.

Thus, it had some sensitive information from military bases across the globe. But, (you guessed it) the platform API breach led to huge losses.

2019 – Facebook Data Breach

Facebook is the most popular social media app right now. And the platform contains the data of billions of people including phone numbers, names, and personal messages.

But all of it was lost to a hacker back in 2019. The leak targeted two datasets from third-party Facebook apps.

2021 – LinkedIn API Breach

Well, well, who doesn’t know Linkedin, the popular job search platform? And as it turns out, the public API platform used without any authentication was actually breached in 2021.

The leak was so huge that the platform lost the data of 92% of users. In other terms, this means 700 million users.

2022 – T-Mobile API Breach

T-mobile is one of the largest phone service providers in the USA. Despite this, it faced a data breach with one of its APIs just back in 2022. Well, it resulted in the leak of 37 million users’ personal information.

And with this out of the way, let’s look at some of the most common threats to API security.

API Security Threats

There are various types of threats to API security. So, before we discuss the API security best practices and other things along the line, let’s look at some of the most common threats to API security.

Here are some of  the most common API security breaches as per the Open Web Application Security Project (OWASP):

API Security RiskDescription
Broken Object-Level AuthorizationAPIs that don’t enforce proper authorization checks on individual objects can allow attackers to access sensitive data or perform unauthorized actions.
Broken User AuthenticationApplication Programming Interface that has weak or broken authentication mechanisms can allow attackers to impersonate legitimate users, steal credentials, or perform unauthorized actions.
Excessive Data ExposureIf too much data is exposed, it can put sensitive information at risk of exposure or theft.
Lack of Resources and Rate LimitingAPIs that don’t implement proper resource management or rate limiting can be vulnerable to denial of service attacks or excessive usage.
Broken Function-Level AuthorizationWhen APIs don’t enforce proper authorization checks on individual functions, it can allow attackers to perform unauthorized actions.
Mass AssignmentAPIs that allow mass assignment of input parameters can be vulnerable to injection attacks or unauthorized access.
Security MisconfigurationAgain,  API misconfigured can be vulnerable to a wide range of security risks, including data breaches, injection attacks, or denial of service attacks.
InjectionAPIs that don’t properly validate user input can be vulnerable to injection attacks, such as SQL injection or cross-site scripting (XSS).
Improper Asset ManagementAPIs that don’t properly manage assets, such as keys or tokens, can be vulnerable to theft or misuse.
Insufficient Logging and MonitoringHere, APIs that don’t log and monitor activity can be vulnerable to attacks or breaches that go unnoticed. To mitigate this risk,

How To Secure API? API Security Best Practices

API Security App Practices

So, how do you secure API against the security threats we discussed above? Well, there are various API security best practices. And we shall be discussing a number of those here. Therefore, let’s get right into it:

1. Vulnerability Identification

It goes without saying that if you want to secure an API, you first have to identify the potential insecurities

Now, this is easier said than done. And it becomes even harder if the solution is dealing with a large number of APIs.

Furthermore, one has to consider the entire API development lifecycle. As such, all steps from planning through development, testing, staging, and production should be considered.

This is the first thing to consider.

Moving on, let’s see the next process.

2. Use Tokens To Improve API Security

Once you are done with identifying, it’s time to improve the security system via a technology called a token.

API security tokens work something like this: the token is used to communicate and they are required to authenticate before passing the information.

These tokens allow controlled access to resources. The reason is that any interacting software that doesn’t have a proper token will be rejected. This is how your tokens improve overall security thus making it one of the API security best practices.

3. API Gateway Security

Well, well, we have heard many times the term “API gateway”.

But what is it exactly?

An API Gateway security stands as a gate between client and backend services. Thus, it serves as a reverse proxy since it allows traffic to pass and authenticate the same as per predetermined standards.

In this way, the API gateway improves the security of the platform by large.

4. OAuth

Let us introduce you to one of the most important things in the API security scenario, Oauth. As such, OAuth is a powerful tool for controlling API access.

It is a token-based authentication frame. And enables third parties to access important information without user credentials disclosure.

It allows controlled access for authentication and authorization. And for that reason, it’s quite popular among API developers.

5. Data Encryption

Here’s one of the oldest tricks in the book to secure data.

Well, data is sensitive and one of the oldest ways to secure it is encryption. For those who don’t know encrypting data makes it unreadable unless you have the code used to encrypt it.

API deals with a lot of data including (and especially ) personally identifiable information (PII). To ensure this data is safe, the API security standards require companies to encrypt

So, even if someone is able to get access to the data, they won’t have the code to make it readable.

6. Rate Limiting and Throttling

As we discussed previously, one of the most common types of cyber-attack for APIs are denial of service (DoS) attacks.

To protect the API against this, app and web developers often limit the frequency of API calls. It works well to protect the solution during high traffic, thus, driving performance and high end security.

Moreover, it also helps create balance between availability and access via user connection regulation. Therefore, this is something that you must consider for securing API.

7. Service Mesh

Service mesh is much like API gateway. Here’s How: Service mesh technology creates multi-layer management and control system. This happens when one service requesting routing.

As such, service mesh creating a perfect flow of different parts working together, creating a streamline between  correct authentication, access control and other security measures.

Today, service mesh has become one of the most common technology for APU security. Therefore, this is something that you should definitely consider.

8.Zero-trust Philosophy

This is exactly as it sounds. Zero trust philosophy assumes there no system that is to be trusted even if they exist within the security parameter until proven other

Therefore, when communicating with the API, they have to authenticate their identity, improving overall security of API.

Zero trust philosophy uses technologies such as as OAuth 2.0, API keys, and SSL/TLS encryption i.e. the ones we discussed above.

With all said and done, it’s time to test the API. And here’s how we do it.

API Security Testing – Methods

Once you have implemented the API crescirty best practices, it’s time to test the API.

As such, API security testing involves a range of techniques designed to identify vulnerabilities in APIs and ensure that they are secure from attacks.

These techniques can help organizations to identify and remediate potential security risks in their APIs before they can be exploited by attackers.

API Security Testing TechniquesDescription
Parameter Tampering TestingBeing one of the most common, this testing method involves modifying parameters in API requests to check if the API is properly validating and sanitizing input. This can include testing for SQL injection, XSS, and other types of vulnerabilities.
Command Injection TestingThis is a testing technique that involves injecting malicious commands into API requests to check if the API is properly validating and sanitizing input. This can help to identify vulnerabilities that could allow attackers to execute arbitrary commands on the server hosting the API.
API Input Fuzzing TestingFuzzing Testing technique involves sending malformed or unexpected input to the API to check how it handles errors and exceptions. This can help to identify vulnerabilities such as buffer overflows or denial-of-service attacks.
Unhandled HTTP Methods TestingThis testing technique involves sending HTTP requests using methods that the API is not designed to handle, such as TRACE or DELETE. This can help to identify vulnerabilities in the API’s handling of HTTP requests and responses.


Top Open Source API Testing Tools

API testing tool

To improve API security testing, you can incorporate tools. Therefore, let’s look  at the API security testing tools below:

  •  Postman
  • SoapUI
  • Swagger
  • JMeter
  • Assertible
  • RestAssured
  • Karate
  • Newman
  • Insomnia
  • Apache Bench

API Security Checklist

Securing API can be difficult and confusing since it has so many steps. And to help you with just that, here’s a API security Checklist that you may follow.

It Is, as mentioned below:

  • Authentication and Authorization
  • Encryption
  • Input Validation and Sanitization
  • Rate Limiting
  • Audit Logging
  • Vulnerability Scanning
  • Monitoring and Alerting
  • API Documentation
  • Penetration Testing
  • Continuous Improvement

And with this, we are done with the blog.


API security is a rising business concern considering the importance of API security. If you are someone new to the concept and want to integrate an API securely in your web app or mobile app, you should contact a mobile app development company.

Apart from that, we discussed all you need to know about API security. With this, we conclude the blog.


Some best practices for API security include:

  • strong authentication and authorization mechanisms
  • encryption to protect data
  • validating and sanitizing input
  • rate limiting and throttling
  • API gateway
  • monitoring and logging API activit
  • assessing the security of the API

API security testing focuses specifically on testing the security of APIs, while traditional web application testing includes testing the security of web applications as a whole. API security testing can involve both manual and automated testing techniques, such as static analysis, dynamic analysis, and penetration testing.

Some common vulnerabilities in APIs include broken authentication and access control, injection attacks, cross-site scripting (XSS), excessive data exposure, and security misconfiguration.

An API gateway is a tool that can be used to manage API traffic and apply security policies, such as authentication, authorization, and rate limiting, to incoming requests. The API gateway can also be used to log and monitor API activity, which can help to detect security incidents in real-time.

Organizations can ensure the security of third-party APIs by conducting a thorough security assessment before integrating the API into their applications. This should include reviewing the API documentation, testing the API for vulnerabilities, and verifying that the API provider has appropriate security controls in place.

API security is particularly important in the context of microservices architecture, as microservices are often interconnected through APIs and vulnerabilities in one API can have a ripple effect throughout the entire architecture. Implementing strong API security measures can help to mitigate these risks and ensure the overall security of the microservices architecture.