Many websites or applications we use have the facility to log in using Google or Apple credentials. This is made possible by Google and Apple allowing access to their log-in systems through the use of APIs. APIs are also used to secure data access on a website, especially when handling sensitive or business-critical information. Before we dive into API keys, let’s briefly review what APIs are.
What is an Application Programming Interface (API)?
APIs are protocols that two computing systems use to communicate with each other – more specifically, APIs are the set of rules and syntax for communication. The systems cannot access the other’s internals, so the communication happens over the API layer which is separate from the internal systems.
Applications abide by the protocols defined for the required inputs and outputs and send requests to the API endpoints. Most APIs will have extensive documentation on how to communicate with the endpoints.
APIs typically communicate over the hypertext transfer protocol (HTTP), and securing this protocol—such as by using HTTPS instead of plain HTTP—is important for protecting data exchanged between systems.
When an application developer wants to include a log-in with Google credentials, they’ll need to understand how to integrate Google sign-in with APIs into their app. The app must adhere to the rules and syntax prescribed by Google to access the information required to enable the Google sign-in. The developer and the application are unable to access the internal systems of Google and can only communicate with the API layer of Google sign-in.
There are some APIs that can be accessed without authentication. But for others that require authentication when requests are sent to API endpoints, API keys are required to authenticate the request.
How API Keys Work
API keys are unique values that API providers use to identify and authenticate requests. Typically, API keys are associated with a specific project or application, not with individual users, and are used to identify the client making the API call. This helps to ensure that the API provider gives access to the data or functionality only to approved users of the API service. API keys serve as the identifier for the project or client application using the API. To gain API keys for a service, the developer must first register with the API provider. The API provider will then assign the developer a unique identifier or API key, which the application must pass along with the request to the API endpoints. To generate an API key, the developer usually logs into the platform, navigates to the API section, selects the relevant project, and generates the key.
For API services that require authentication, every request should have an API key. The API key is sent with each API call to authenticate the client application, but it does not reliably authenticate individual users. The API service verifies the key for each request and if the API key is invalid, an error response is generated. If the API key is valid and the request is in the required format, the requested data is provided.
Application developers must ensure the API keys are kept secure. API keys are secret tokens that should be kept confidential and never exposed publicly. If a key falls into the wrong hands, it can be used to attack a service, and the attack will then be logged as if the developer were responsible.
Uses for API Keys
With the rise of microservices architectures and the need to communicate with various services, APIs have become widely used, with most services now requiring API keys for access. The major uses of API keys are discussed briefly in the following sections. Developers use API keys to secure API access, grant access to specific projects, and manage project authorization.
API services that require authorization cannot be used without API keys. Since every request should have an API key, they can be used to authenticate users. Requests to endpoints without API keys are rejected, and API requests without a valid key are also rejected. This way API keys help to ensure that only authorized users can access the service.
Identification
API keys are unique identifiers for each registered user of the API service, and the key must be used with every request. API keys are primarily used to identify the application making the request, rather than the individual user. This helps the service identify who is sending that particular request.
Tracking
The usage pattern of every user can also be tracked by API keys. API keys enable usage tracking, help identify usage patterns, monitor application traffic, and detect malicious activity. The request, frequency, IP address, and various other parameters can all be tracked using the developer’s unique API key.
Limits
Most APIs have limits to their use, which can then be enforced with API keys. API keys are used to enforce rate limiting, set rate limits, apply controls, and prevent abuse of the API. Since user requests are tracked with the keys, it can be used to identify whether a user has exceeded the limits. Once the limit for an API key is crossed, additional data will not be provided to the user. Tracking users with keys can also be used to identify violators and block service to those users.
Audits
Requests to API services are logged and tracked with API keys. The API server is responsible for logging these requests, and server logs are used to perform audits. This is a record of how the service was used and by whom, and this log can be used to perform audits. For example, an audit can help to determine the root cause of a cyberattack or to analyze how users are using the service. This information can then be used to make improvements. Regardless of the purpose of the audit, API keys provide a simple way to perform audits of all the requests made to the service.
API Security
API security is essential for protecting sensitive data and maintaining the trustworthiness of your applications. API keys play a crucial role in API security by acting as unique identifiers that authenticate and authorize clients accessing API services. By requiring API keys, API providers can control who has access to their data and services, helping to prevent unauthorized access and potential data breaches. However, simply using API keys is not enough—if keys are exposed or mismanaged, attackers can gain access to sensitive data. To keep your API keys secure, it’s important to implement extra layers of security, such as encrypting keys during storage and transmission, using secure protocols like HTTPS, and regularly updating your security practices. By prioritizing API security and treating API keys as sensitive data, you can help ensure that only trusted clients can access your API services and that your data remains protected.
Best Practices for API Keys
To keep your API keys secure and your applications safe, it’s important to follow industry best practices. First, never share your API keys publicly or include them in public code repositories, as this can expose your services to unauthorized access. Store your API keys in secure locations, such as encrypted environment variables or password managers, rather than hardcoding them into your application code. Regularly rotate your API keys to reduce the risk of compromised keys being used for malicious purposes. Monitor your API usage closely to detect unusual activity or potential abuse, and set up alerts for suspicious patterns. Restrict API keys to specific IP addresses and limit their access rights to only the necessary functionality—such as read only access or write access—required by your application. By following these best practices, you can help ensure your API keys remain secure and your API usage is protected from unauthorized access.
API Key Management
Effective API key management is vital for maintaining the security and reliability of your API services. This process involves generating new API keys for developers or applications, distributing them securely, and revoking old or compromised keys as needed. A robust API key management system allows you to monitor API usage, track which keys are being used, and quickly identify any suspicious activity. By managing your API keys carefully, you can control access to your services, prevent unauthorized use, and ensure that only trusted clients can interact with your APIs. Regularly reviewing and updating your API key management policies helps maintain a high level of security and keeps your API services protected.
API Key Rotation
API key rotation is a proactive security measure that involves regularly updating your API keys to minimize the risk of unauthorized access. Developers should rotate their API keys every 90 to 180 days, or more frequently if their application handles highly sensitive data or is subject to strict security requirements. By rotating API keys on a regular schedule, you reduce the window of opportunity for attackers to exploit compromised keys. Implementing a reliable API key rotation process—such as automated reminders and seamless key replacement—ensures that your API keys remain secure and your services are protected. Regular rotation, combined with secure storage and careful monitoring, helps developers maintain strong API security and safeguard their applications from potential threats.
API Keys: Simple Yet Powerful
In summary, API keys are used to authenticate users to a service, but they also have a wide range of uses beyond authentication. All application developers and services today use APIs as a communication layer, which helps to make developers' lives easier.
For example, setting up a notification system is a cumbersome and time-consuming task, but you can register and gain access to an API key for a service like MagicBell to implement such a system. This ability to set up a complete notification system in mere minutes is made possible through the use of APIs and authentication with API keys.