Frank is deeply worried about attacks on his company's e-commerce server. He is particularly concerned about cross-site scripting and SQL injection. The BEST defense against these two specific attacks is _________.

Encrypting the web traffic will not have any effect on these two attacks. A web application firewall (WAF) might mitigate these attacks, but it would be secondary to input validation, and an intrusion detection system (IDS) will simply detect the attack, it won’t stop it.