iSACA Cybersecurity Fundamentals Certification Practice Exam

What is one advantage of using a symmetric key?

1. It is more secure than asymmetric keys

2. Only one key is needed for both encryption and decryption

3. It can be distributed easily among users

4. It allows for signing electronic documents

The correct answer is: Only one key is needed for both encryption and decryption

Using a symmetric key presents a notable advantage in that it requires only one key for the processes of encryption and decryption. This means that the same key is used to both encode the data and decode it, simplifying the key management process. In scenarios where both parties have access to the shared key, communication can be streamlined, as they do not need to exchange multiple keys for successful encryption and decryption. This efficiency can make symmetric key algorithms faster and less resource-intensive compared to asymmetric key systems, where different keys are required for each operation. Hence, the simplicity of managing a single key is particularly beneficial in environments where rapid encryption and decryption are crucial, such as in performance-sensitive applications. In contrast, the other options highlight advantages that are typically more associated with asymmetric keys or misunderstand aspects of symmetric key use. For instance, the security of symmetric keys can be impressive, but it is context-dependent and not inherently more secure than asymmetric counterparts. Distribution issues can arise since sharing the single symmetric key among users must be executed securely to avoid compromising it. Finally, signing electronic documents typically requires asymmetric keys to ensure authenticity and non-repudiation, which is not a function that symmetric keys fulfill.