What is API security?

API security refers to the practice of preventing or mitigating attacks on APIs. Considering that APIs are one of the nerve centers of software ecosystems today (because they enable different applications to communicate and exchange data exchange between each other), API security is definitely an essential part of an organization's security posture.

In modern cloud-native applications, APIs power everything—from mobile apps to payment gateways. However, they also expand the attack surface because poorly secured APIs can expose sensitive customer data or provide entry points for malicious actors.

Key aspects of API security include authentication (what is the identity of users or applications attempting to access the API), authorization (what specific action/resource can the app/user perform or access through the API), data encryption (protecting data that's both in transit or at rest), input validation (does the data received through an API request conform to the right formats), rate limiting (controlling the number of requests an API can receive within a given timeframe), and of course monitoring and auditing (continuously tracking API usage and activity to detect suspicious behavior). Common threats include injection attacks, credential stuffing, and data exfiltration.

So, as you can see, an organization must adopt a multi-layered approach that considers the entire API lifecycle, from design and development to deployment and ongoing maintenance, to be able to mitigate risks at every level.