Key API Security Principles And How To Implement Them

By   Musa Nadir Sani
Cyber Threat Intelligence Analyst , CyberSOC | Oct 27, 2022 06:37 am PST

Application programming interfaces (APIs) over the past couple of years have become a key element in modern application development, allowing for seamless communication and integration between software all over the internet. A recent study shows 65% of organizations rely on APIs to improve collaboration with partners and more than half (53%) consume third-party APIs as part of their development.

With their popularity increasing and their usage also following a similar rise, APIs can pose a high-security risk to organizations and individuals who use them due to the sensitivity of data that is regularly sent through them.  If these sensitive data are to be somehow exposed, it can lead to dire consequences for organizations. API security thus should become a top priority in the minds of security engineers and overall IT decision-makers.

What is API Security and why is it important?

APIs can be defined as the totality of the procedures and programs put in place to ensure that existing APIs follow the best security practices and newly built APIs are done so in accordance with the best enterprise security standards.

APIs have naturally become one of the top attack vectors for cyber-attacks over the past 12 months. According to a recent report, API attack traffic grew by 681% with 95% of companies reporting an API security incident over the past 12 months. The need to adopt better API security practices is at an all-time high as existing security measures are simply not suitable enough.

API security is thus important to keep attackers away and ensure that sensitive data transmitted via APIs are left safe and in line with the security principles of confidentiality, Integrity, and availability.

Key API Security Principles and how to implement them

When building APIs and following the necessary security principles necessary, it is normal to face challenges right at the onset. This is because the entirety of the process is a cyclical one that involves testing code while building to ensure that they are up to standard and are as secure as possible. This can seem like a daunting and long-drawn process. However, it is a necessary one because poorly designed API security can lead to misuse or in extreme cases, non-use by the intended client.

Good API security principles must rest on the foundations of:

Authentication: Authentication is the process of recognizing a user’s identity. This means that your API security principle must have in place the right authentication for the people and programs that are to use your API.

Authorization: Authorization is the process of granting or denying access to resources. Simply put, you should put principles in place to strictly authorize users and programs to perform certain tasks on your API.

Accountability: API security principles should ensure that all API calls made are traceable to ensure accountability to all parties involved in API usage.

The three main principles of API Security

Identity and access management (IAM): Identity and access management (IAM) is a set of policies and technologies to ensure that the right users in an enterprise ecosystem have the right privileges and access to technology resources. Managing identity and access ensure that all applications, servers, and users that consume your API have the appropriate permissions. Authorization and authentication are the two primary methods for managing identity and access.

Authorization deals with what someone can do, while authentication is concerned with who someone is. Authentication and authorization are used to enforce access control of API calls.

Implementation of IAM policies can be done through multi-factor authentication, End User Identity Management. Privacy Management, Identity Federation and Social Login, Extended Access Delegation Capabilities, Cross Protocol Single Sign On and Sign Out, and Enforced authorization.

Content integrity and confidentiality: After ensuring proper Identity and access management when planning API security, the next step would be to secure communications made using API calls. Content integrity and confidentiality summarily mean that whatever data is transmitted via APIs is not only received without being modified in transit but also was not seen by unauthorized personnel.

Implementation of integrity and confidentiality can be done via digital signatures and cryptography. A digital signature is an electronic, encrypted, stamp of authentication on digital information such as email messages, macros, or electronic documents. Basically with an API, the application creates a digital signature with a secret code. The API then uses the same algorithm used to create the digital signature with a new secret code to produce its signature and compares it to the incoming signature.

With cryptography, asymmetric cryptography is used to create a key pair to encrypt data that can only be encrypted with the corresponding key.

Reliability and availability: API security should ensure that APIs are always available to respond to API calls and execute the necessary requests from the calls without much hassle and in the right time frame without any data loss or exposed vulnerability.

It is important to note that most applications exist on the cloud with several integrations to other cloud and premise services.

Thus, implementing the availability and reliability of APIs can be achieved by horizontally scaling the API across multiple servers and handing off the processing of the message to a message broker, which will hold it until the API has finished processing it.

The three principles above represent the most important principles of API security. However, other principles are also put in place to ensure APIs are as secure as possible and follow the right compliance standards. The following represent other API security principles;

  • There should be a balance between security and performance concerning key lifetimes and encryption/decryption overheads.
  • Secure coding practices should be adopted by developers in line with the OWASP standards.
  • Security testing should also be adopted during the development cycle of APIs and applications in general.
  • IAM policies should also be assigned to API users based on the policies of least privilege to ensure a minimal amount of access is needed by users to carry out the functions required.
  • A common authentication and authorization pattern should also be used. Avoid using bespoke solutions for each API.
  • Randomness should be maximized for user credentials by replacing usernames and passwords for API authorization with API keys. API keys are more secure and provide a more challenging attack surface for attackers.
  • API designs should have security in mind from the onset. This ensures that the right foundations are set and it allows for security testing during the development cycle.


Organizations need to adopt the right API security principles to ensure complete protection of their APIs, software, and enterprise environment at large. This would help them mitigate against the ever-growing threat landscape using APIs as an attack vector.

API principles on the other hand continue to evolve as more thought is being put through to safeguard API usage. Nevertheless, the principles listed above represent the very best in industry standards. Organizations and individuals are thus required to make use of them to ensure their APIs and applications are safe to use.