As API development becomes such a routine part of daily business operations, API security is a growing concern. Application programming interfaces, or APIs, work on the framework of web and mobile applications, making their backend data transfer essential to protect at all costs.

To understand the importance of security in the API world, you must first understand what APIs are, how they transmit data, and what security options are available.

What are APIs?

An API is what defines how software interacts, both internally and externally, with other programs. APIs on websites and applications in the Internet of Things (IoT) are often used to gather and process user input. An API can control:

  • The types of requests between programs
  • How requests are made
  • Data formats used for transmission

Let's use Google Maps as an example—an API runs this software platform, allowing web designers and others to embed the Google Maps application into their website or another page. When the Maps application is used, it is accessed through a prewritten API that Google created.

Essentially, APIs make integrating applications and software easily into websites, other applications, and more. API security refers to all the APIs you own and those used indirectly, such as in the example of Google Maps above.

This mechanism allows software applications to interact without line-by-line coding or additional work of developers and programmers. It also allows applications to access data stored on remote servers so that it doesn't have to be stored locally.

As you can see, security must be in place with all this data going back and forth.

Build Powerful SMS Campaigns

No contracts, no hidden fees, and no credit card information required to get started.

Create Account
a man in suit smiling as he looks down at his cellphone

API Security Standards

In performing routine API security testing, certain standards and best practices must always be considered. There are several aspects of security to consider, including those listed below.


Encryption is a standard tool used today in security. It disguises data with certain encryption tools so it cannot be deciphered without the proper "key" to decode the message. Otherwise, it appears to be unreadable content and, therefore, cannot be used by unauthorized sources.


One of the first steps in web API security is understanding your system's potential threats and vulnerabilities. Look for signature-based attacks, use rate limits to protect the backend of APIs, and consider using stricter rules for your JavaScript development, for example.


A security token requires that the token be authenticated on one side of the communication before it can be sent or received. This can help allocate network resources and ensure that only the right people interact with the right communications and data.

OAuth and OpenID Connect

Open authorization, or OAuth, dictates how tokens are accessed on the client side. The OpenID Connect layer sits on top of OAuth, allowing clients to check end-user identities and validate access. This limits the transfer of information to only those who are authorized.

API Gateways

The API gateway sits between the backend services and the client, providing a proxy for traffic to pass through. The traffic is authenticated on pass-through based on standards that were previously set.

Throttling and Quotas

Throttling is designed to limit the data transfer speeds used, which can help thwart potential attacks designed to bombard your system. Quotas are designed to limit how much data can be transferred, which prevents attacks on large data networks. These protect bandwidth by limiting system access and protecting its resources.

Zero-Trust Security

Using zero-trust security assumes that no traffic can be trusted. This means that all users will need to have their rights to access authenticated before they can access an API or a network. This provides additional security for applications and data by ensuring unauthorized users cannot access a system, including imposters that may impersonate previously authenticated users.

Essentially, with a zero-trust approach, the device and the user are assumed to be untrustworthy until authenticated.

REST vs. SOAP API Security

Representational state transfer (REST) security is a common choice for APIs and their networks. This type of API security includes an HTTP Uniform Resource Identifier (URI) that controls what data can be accessed by the API during operation. This prevents various attacks, including those aimed at malicious data used to hack or introduce a virus to a system.

REST supports HTTPS (secure HTTP connections), transport layer security (TLS), and secure sockets layer (SSL) encryption. It can also be secured with customized tokens to your needs, providing additional protection. This type of security essentially provides two functions:

  1. Examining and monitoring data that is moving into and out of the API.
  2. Blocking attempts to damage the application or hack into the system and steal data.

SOAP, or Simple Object Access Protocol, is the other security option in APIs. It is designed to protect the transfer of information between devices, using SAML tokens and XML signatures to authorize messages and authenticate data transfers. This ensures that attackers can't gain access because there are dedicated "signatures" or keys that are required.

REST doesn't require the routing or parsing of information that SOAP does, but SOAP is often easier to design and operate without major modifications. Whether you choose or use a combination of both, ensure you understand them and how to implement them effectively for the best results.

Protect Your APIs with Better Sourcing and Partnerships

You can also explore the API solutions available from Esendex, which can be used for SMS, MMS, voice broadcasting, phone verification, and more. Contact us today to discuss your API security needs and how we can help.

An SMS broadcasting software displayed on a laptop screen
Become a Reseller

Our SMS reseller program gives you everything you need to easily resell our SMS software to your customers and increase revenue.

A cellphone that has text messages displayed on its screen that came from an sms api

Texting API designed to send & receive SMS & MMS globally using a short code or 10DLC number.

An SMS broadcasting software displayed on a laptop screen
SMS Software

Easy to use SMS software that can send & receive SMS & MMS using a short code or 10DLC number.

A phone with a headset sitting next to it
Voice API

Powerful voice API that sends mass automated phone calls quickly to mobile & landline devices.

A cellphone with a check on the screen and the words verified beneath the check
Verification API

Verify mobile & landline numbers, find service providers, & define time zones to restrict calling times.

people sitting at a table in a resturaunt and all of them are looking at their cellphones

What Is Mass Texting & How Does It Work?

Businesses can utilize SMS marketing in a number of ways, such as through a long code or short code. Short codes...

Read More
A man holding a phone in front of a laptop and both have marketing data displayed on their screen

What Is SMS Marketing & Why Use It?

SMS marketing is a term that's often thrown around when companies are talking about their communication...

Read More
A man pondering at a latop with a pen to his lip

SMS vs. MMS (What's the Difference)

Mobile phones have become a commodity. Today, people use cellular devices to connect with the world...

Read More