Which of the following is a method to harden a web application?

Implementing SSL encryption is a fundamental method to harden a web application. SSL (Secure Sockets Layer) encrypts the data transmitted between a user's browser and the web server, preventing attackers from easily intercepting or tampering with sensitive information, such as passwords, credit card numbers, and personal data. By ensuring that all data in transit is encrypted, SSL helps maintain confidentiality and integrity, making it significantly more difficult for malicious actors to exploit vulnerabilities in the application.

This encryption not only protects user data during transmission but also instills trust in users, as they see secure indicators in their browsers, such as HTTPS and the padlock icon. This is particularly important for any web application that handles sensitive or private information, reinforcing the overall security posture of the application and its ability to handle potential threats from attackers.