How can one protect against SQL injection attacks?

Employing input validation is a critical defense mechanism against SQL injection attacks. SQL injection occurs when an attacker is able to manipulate a web application's database query by injecting malicious SQL code through user input fields. By implementing strict input validation, you ensure that only valid input is processed by the application. This involves checking the data for type, length, format, and range before it is passed to the SQL query.

Input validation can include techniques such as allowing only expected characters (e.g., alphanumeric only), setting proper length limits on input fields, and using prepared statements or parameterized queries that separate user input from the query itself. This significantly reduces the likelihood of harmful SQL code being executed, effectively safeguarding the database from unauthorized access and potential data breaches.

While other options might be relevant in a broader security context, they do not address the specific vulnerability posed by SQL injection. For instance, unencrypted connections may expose data to interception but do not prevent an attacker from executing injection techniques. Increasing server speed or limiting database size does not mitigate the risk of SQL injection, as these actions do not address the way user inputs are handled or validated. Hence, input validation stands out as the most effective preventive measure against SQL injection attacks.