Ensuring web security while implementing a payment gateway API is crucial to protecting user data and preventing fraud. Here are key steps to follow:

1. Use HTTPS (SSL/TLS Encryption)
Install an SSL/TLS certificate to enable HTTPS.
Encrypt all data transmitted between the user, server, and payment gateway.
2. Implement Secure Authentication & Authorization
Use strong API keys and OAuth tokens instead of exposing credentials.
Restrict API access with IP whitelisting and role-based access control (RBAC).
3. Validate & Sanitize User Inputs
Prevent SQL injection and XSS attacks by sanitizing input data.
Use prepared statements when handling database queries.
4. Enable Web Application Firewall (WAF)
Protect against DDoS attacks, brute force attacks, and other threats.
Use Hostinger’s security tools (since you’re hosted there) or cloud-based WAF services.
5. Implement Razorpay Webhooks Securely
Verify webhook signatures using Razorpay’s Webhook Secret.
Process only validated events to prevent spoofing.
6. Use Tokenization for Card Data
Avoid storing sensitive payment data. Use tokenization to replace card details with secure tokens.
7. Enforce Strong Password Policies
Require strong passwords and enable multi-factor authentication (MFA) for admin access.
8. Regularly Update Software & Plugins
Keep PHP, MySQL, and all plugins updated to fix security vulnerabilities.
9. Monitor & Log Transactions
Enable real-time logging to track suspicious transactions.
Use fraud detection tools to detect unusual payment activity.
10. Comply with PCI DSS Standards
Follow PCI DSS guidelines to ensure secure payment processing.
Avoid storing CVV and other sensitive payment details.