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12 API Security Best Practices to Safeguard Your Data

"Security is not a product, but a process." - Bruce Schneier.

APIs play a crucial role in today's digital landscape, acting as the gatekeepers to valuable data and resources. However, with increased reliance on APIs comes increased responsibility to secure them. The world is filled with all sorts of nefarious characters who will stop at nothing to access sensitive information, making API security a top priority for businesses of all sizes. 

Per a survey, 41% of organizations who participated experienced an API security incident in the past 12 months, while 63% specified that these incidents also included data breaches.

That's why, in this blog post, we're sharing 12 API security best practices to safeguard your data and keep your organization safe from harm. From using HTTPS and implementing access controls to conducting regular security audits and monitoring logs, we've got you covered. So sit back, relax, and take notes, because we're about to take you on a journey through the best ways to secure your APIs.

For a quick sneak peek, here are the most common API security best practices:

  1. Strong Authentication and Authorization
  2. Implement Access Control
  3. Encrypt Requests and Responses
  4. Understand the Full Scope of Secure API Consumption
  5. Always Use a Gateway
  6. Use a Central OAuth Server
  7.  Monitor and Log API Activity
  8. Validate Input
  9. Use Rate Limiting
  10. Implement DDOS Protection
  11. Conduct Regular Security Audits

What is API security?

API security involves protecting the communication channels between APIs and the systems that use them from unauthorized access, data breaches, and other malicious attacks. This means ensuring that only authorized users can access and manipulate data and that sensitive information is protected while in transit.

This involves ensuring the confidentiality, integrity, and availability of sensitive information while it is being transmitted between systems and applications. Ultimately it aims to prevent unauthorized access to the API and its associated data, to protect sensitive information from being intercepted or viewed by unauthorized users, and to ensure that the API is available for use by authorized users.

According to a study conducted by Salt Security, 42% of participants change APIs daily or weekly.

Why is API security important?

API security is critical for organizations as it helps protect sensitive data, maintain system integrity, comply with regulations, protect brand reputation, and avoid legal liability.

‚úď Protecting sensitive information: APIs are like digital highways that transfer important information such as financial transactions, personal data, and confidential business secrets. If these highways aren't secure, anyone can hop on and access this information, leading to data breaches, identity theft, and other cyber attacks.

‚úď Maintaining smooth operations: APIs are the glue that holds different systems and applications together, allowing them to work in harmony. If API security is lacking, malicious actors can manipulate the data being shared, causing system failures and errors that can bring your business to a grinding halt.

‚úď Staying on the right side of the law: Many industries have strict regulations that govern the handling of sensitive information. For instance, the Payment Card Industry Data Security Standard (PCI DSS) requires organizations to secure their APIs and protect payment information. Failure to comply can result in hefty fines and loss of business. See our free compliance frameworks guide.

‚úď Preserving your good name: Data breaches and security incidents can tarnish an organization's reputation, causing customers to lose trust and resulting in a decline in business. By ensuring the security of your APIs, you can protect your reputation and keep your customers confident in your abilities.

‚úď Avoiding legal trouble: In the event of a data breach or security incident, organizations can be held responsible and sued for damages. Implementing proper API security measures can reduce your legal exposure and prevent costly legal battles.

Common API security risks

APIs play a crucial role in driving the technological advancements of today, but with their widespread use come a variety of security risks that can put sensitive information and businesses at risk. To protect your valuable data, it's important to be aware of the most prevalent API security threats. Here are some of the top API security risks you need to keep an eye out for:

Injection Attacks: Injection attacks can occur when malicious actors inject harmful code into an API, leading to data manipulation and theft of sensitive information. Protect your API from SQL injection attacks by implementing proper input validation and sanitization.

Broken Authentication and Access Control: Neglecting proper authentication and access control measures can lead to unauthorized access to sensitive data and systems. Ensure your API implements strong user authentication and role-based access control to prevent these types of security incidents.

Insufficient Logging and Monitoring: Without proper logging and monitoring systems in place, it's difficult to detect and respond to API security incidents. Invest in robust logging and monitoring solutions to stay ahead of potential threats.

Lack of Encryption: Ensure the secure transmission of sensitive information by properly encrypting data as it travels through your API. This will help protect against data interception and exploitation by malicious actors.

Unvalidated Inputs: User-generated input often contains malicious code that can result in security vulnerabilities. Implement a proper input validation policy to protect your API against unvalidated input attacks.

Below you can see a table that explains and matches common API attack types and traditional mitigations for each.

Attack Type Mitigation
SQL Injection Validate and sanitize user input, use parameterized queries, limit user privileges
Cross-Site Scripting (XSS) Escape user input, sanitize user input, validate user input, use HTTP-only cookies
Broken Authentication and Session Management Use strong passwords, implement password salting and hashing, implement multi-factor authentication, use HTTPS
Cross-Site Request Forgery (CSRF) Verify that requests came from the same source, use anti-CSRF tokens, implement Same-Site Cookies
Remote Code Execution Validate and sanitize user input, implement least privilege, keep software updated and patched
Injection Flaws Validate and sanitize user input, use parameterized queries, use white-listing
Broken Access Control mplement access control checks, restrict access to sensitive data, limit user privileges
Insufficient Logging & Monitoring Monitor logs regularly, log events, log activity, implement real-time alerting
Server Misconfiguration Follow secure server configuration guidelines, keep software updated and patched, limit user privileges

Top API security best practices you should implement

1. Strong Authentication and Authorization

Implementing strong authentication and authorization mechanisms such as OAuth, OpenID Connect, or JSON Web Tokens (JWT) is essential for verifying the identity of API users and ensuring that only authorized users have access to API resources. For example, if you want to grant access to an API resource to a third-party application, you could use OAuth to create an access token that the application can use to access the resource.

The access token would include information about the user and the application's access rights and would be encrypted to prevent unauthorized access.

2. Implement Access Control

To further restrict access to API resources, you should use role-based access controls. This means that access to API resources is restricted based on the user's role and the specific permissions they have been granted. For example, an administrator might have full access to all API resources, while a standard user would only have access to a limited subset. Also see Top IAM Security Best Practices.

api security with access control

3. Encrypt Requests and Responses

Encryption is critical for protecting sensitive data in transit. To ensure that data transmitted through your API is protected from eavesdropping and tampering, you should use encryption protocols such as HTTPS or TLS. 

For example, if you're sending sensitive information like a customer's credit card information through your API, you should encrypt the data before sending it and decrypt it only after it has been received. This helps to prevent anyone from intercepting the data and accessing sensitive information.

4. Understand the Full Scope of Secure API Consumption

To fully understand the security implications of API consumption, it is important to be aware of the potential risks involved with third-party APIs and the use of API keys. For example, if your API relies on a third-party API for data, it is important to carefully evaluate the security measures in place for that API, such as encryption and access control, to ensure that the data being transmitted is protected. Additionally, when using API keys, it is important to store them securely and restrict access to them to authorized users only.

Suggested reading: Attack Surface Mapping to understand how expanded your company's attack vectors are.

5. Always Use a Gateway

An API gateway is a crucial component in maintaining API security, as it acts as a control point for access to API resources. An API gateway can enforce security policies such as authentication, authorization, and encryption and can also provide centralized management of security for all APIs in the architecture. 

For example, if an API requires that all requests be encrypted, the API gateway can enforce this policy, ensuring that all requests and responses are protected.

6. Use a Central OAuth Server

OAuth server screenshot

Implementing a central OAuth server to manage authentication and authorization for all APIs in your architecture can help reduce the risk of unauthorized access. A central OAuth server can provide a centralized and secure location for managing user access to API resources, reducing the risk of security vulnerabilities resulting from multiple dispersed authentication mechanisms. 

For example, if multiple APIs in your architecture requires authentication, the central OAuth server can handle authentication for all APIs in a consistent and secure manner, reducing the risk of unauthorized access to sensitive data.

7. Monitor and Log API Activity

Regularly monitoring and logging API activity can help you detect and respond to security incidents in a timely manner. You can use logging tools to track user activity, resource usage, and other key metrics and use this information to detect potential security threats and respond to them quickly.

For example, if you notice a sudden spike in API traffic from an unknown source, you can use logging data to investigate the source and determine if the traffic is legitimate or if it is a malicious attempt to exploit a security vulnerability.

Monitoring your API activity is also essential for ensuring continuous compliance in your organization.

8. Validate Input

Input validation is critical for preventing security vulnerabilities such as SQL injection or cross-site scripting attacks. To validate user input, you should validate all data that is sent to the API, including header values, query parameters, and request bodies. You should validate that data meets the required format, is of the expected type, and falls within expected ranges.

For example, if your API accepts user input to search for products, you can validate that the input is a valid search string and reject requests that include unexpected characters or content.

Suggested reading: 6 Ways to Offer SQL in Your Product

9. Use Rate Limiting

Rate limiting is the process of limiting the number of requests that an API can handle within a specified time period. This helps to prevent denial of service (DoS) attacks, where an attacker floods an API with excessive traffic in an attempt to overload the system.

For example, you can limit the number of requests a single user can make to your API in a given time period to prevent excessive use that could impact the performance and availability of the API.

ddos attack protection

10. Implement DDOS Protection

Distributed denial of service (DDOS) attacks can be devastating to an API and its users. A DDOS attack occurs when a large number of requests are sent to an API simultaneously, overwhelming its servers and making it unavailable. To protect your API against these types of attacks, you should implement DDOS protection measures such as using a content delivery network (CDN) or a cloud-based security service.

A CDN can help distribute the traffic load across multiple servers, reducing the risk of a single server becoming overwhelmed. A cloud-based security service can provide advanced DDOS protection, monitoring incoming traffic and automatically filtering malicious traffic to protect your API from attack.

11. Conduct Regular Security Audits

Regular security audits are essential for ensuring the ongoing security of your API. Security vulnerabilities can arise at any time, and regular security audits can help you identify and remediate these vulnerabilities before they can be exploited.

You should conduct security audits on a regular basis, such as annually or bi-annually, to make sure that your API is secure. During a security audit, you should review your API architecture, access controls, authentication and authorization mechanisms, encryption practices, and other security measures to ensure they are up-to-date and in line with best practices.

Resmo, a cyber asset attack surface management solution, provides an easier way to conduct automated and continuous security audits across your cyber environment, including API keys. It has a free plan, so you can quickly test it to see its benefits firsthand.

api key security on resmo

API key resources you can collect, monitor, and secure with Resmo include:

  • Datadog API Key
  • Linear API Key
  • MongoDB Atlas API Key
  • New Relic API¬†Key
  • Fastly API tokens
  • AWS ApiGatewayV2 API
  • AWS ApiGatewayV2 Stage
  • AWS ApiGateway Rest API

12. Adopt a Zero-Trust approach

Adopting a zero-trust approach to API security is crucial in today's digital landscape, where cyber threats are constantly evolving. Zero-trust means that your API should not blindly trust incoming traffic, even if it appears to be coming from a trusted source.

Using HTTPS for all API traffic and even internally between services can provide encryption and prevent sniffing of sensitive information. Verifying incoming JSON Web Tokens (JWTs) is another important step to ensure the authenticity of incoming requests. Even if the gateway transforms an opaque token into a JWT, it is important for your services to independently verify the token to prevent malicious actors from bypassing your security measures.

By denying access by default and using claims-based access control, your API can enforce access control policies and ensure that only requests that fulfill specific criteria are granted access. This approach helps to mitigate the risk of unauthorized access and protect your sensitive data and resources.


In conclusion, implementing API security best practices is crucial to protect your data and maintain the reliability of your API. From using HTTPS to conducting regular security audits, there are many measures you can take to secure your API. Remember, a secure API is not just about protecting your data but also maintaining the trust of your users and customers.

FAQ: API Security Best Practices

1. How do I provide security to REST API?

To provide security to a REST API, you can implement the following best practices: use HTTPS, limit API access, implement API key security, conduct regular security audits, implement DDOS protection, and adopt a zero-trust approach.

2. What are the types of API security?

API security involves measures to protect the data and functionality of an API from unauthorized access, alteration, or disruption. The following are the common types of API security:

Authentication: Verifying the identity of the API consumer, such as using an API key or OAuth token.

Authorization: Determining if a consumer is allowed to access a specific resource or perform a specific action.

Encryption: Protecting data in transit by encoding it into a secure format, such as HTTPS.

Access control: Defining who is allowed to access an API and what actions they can perform.

3. Which encryption is best for API?

The best encryption for API depends on your specific requirements and the level of security you need to provide. Some common encryption methods include SSL/TLS, AES, RSA, and SHA encryption algorithms.

4. How do I protect API endpoints?

To protect API endpoints, you can implement the following measures: use HTTPS, implement API key security, limit API access, implement DDOS protection, and adopt a zero-trust approach. You can also conduct regular security audits and use network firewalls to monitor incoming and outgoing traffic.

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