Which of the following is a security mechanism that prevents execution of code in certain memory regions?

Data Execution Protection (DEP) is a security mechanism designed specifically to prevent the execution of code in certain areas of memory that should not contain executable code, such as the stack and heap. By enforcing this rule, DEP significantly lowers the risk of certain types of attacks, including buffer overflow exploits, where an attacker attempts to inject and execute malicious code in these non-executable regions.

DEP works by marking specific memory regions as non-executable, allowing only data to be stored there without the risk of executing malicious code. This is crucial for maintaining the integrity and security of a system, as it actively works to prevent unauthorized code execution.

Understanding this mechanism is key to grasping broader cybersecurity practices, as it complements other measures such as ASLR, which randomizes memory layouts to further protect an application's memory. While other options represent important concepts in cybersecurity, they do not serve the specific function of preventing execution in designated memory regions like DEP does.