Web cache poisoning attacks compromise data integrity by exploiting vulnerabilities in caching mechanisms, such as web servers, proxies, and content delivery networks (CDNs). These attacks can deliver malicious payloads, tamper with sensitive information, or redirect users to fraudulent websites. To prevent these attacks, it's essential to establish a strong caching policy that defines what content to cache, for how long, and under what conditions. Other techniques include normalizing cache keys, validating user input, using cache-control headers, not trusting third-party inputs, and deploying web application firewalls (WAFs). Regular monitoring and detection of web traffic, as well as security testing and vulnerability scanning, can also help identify weaknesses that lead to cache poisoning attacks. By following these secure development practices, developers can minimize the risk of a poisoned cache and ensure the integrity of their web applications.