API Key Authentication: Better but Not Best

API Key Authentication: Better but Not Best

API Key authentication improves upon Basic Authentication by using unique keys for each client rather than username/password combinations. API keys are typically long, randomly generated strings that are difficult to guess. Clients include their API key with each request, either in headers, query parameters, or request body.

// JavaScript example of API Key authentication
const axios = require('axios');

const apiKey = 'sk_live_abcdef123456789';

// API key in header (recommended)
const response1 = await axios.get('https://api.example.com/data', {
    headers: {
        'X-API-Key': apiKey
    }
});

// API key in query parameter (less secure)
const response2 = await axios.get(`https://api.example.com/data?api_key=${apiKey}`);

API keys offer several advantages over Basic Authentication. They can be easily generated, revoked, and rotated without affecting user passwords. Different keys can be issued for different applications or environments, improving access control and audit capabilities. Rate limiting and usage tracking become straightforward when each client has a unique identifier.

However, API keys share some vulnerabilities with Basic Authentication. They're static credentials that don't expire automatically, requiring manual rotation policies. If an API key is compromised, it remains valid until explicitly revoked. API keys also don't provide user context – they identify applications but not individual users, making user-specific authorization challenging.