Cisco Certified Network Associate (CCNA) Practice Exam

What is the key difference between asymmetric and symmetric key cryptography?

1. Asymmetric uses one key for both encryption and decryption

2. Symmetric uses two separate keys for encryption and decryption

3. Asymmetric uses two separate keys for encryption and decryption

4. Symmetric is slower than asymmetric key cryptography

The correct answer is: Asymmetric uses two separate keys for encryption and decryption

The key difference between asymmetric and symmetric key cryptography lies in the number of keys used for the encryption and decryption processes. In asymmetric key cryptography, two separate keys are employed: a public key for encryption and a private key for decryption. This means that anyone can encrypt a message using the public key, but only the holder of the private key can decrypt it. This two-key system enhances security and allows for secure communication without needing to share a single key. In contrast, symmetric key cryptography relies on a single key that is used for both encryption and decryption. Both the sender and receiver must have access to the same key, which can introduce potential security vulnerabilities if the key is compromised. Understanding this fundamental difference helps clarify why asymmetric cryptography is often considered more secure for scenarios such as secure key exchange, while symmetric cryptography is typically used for faster encryption and decryption of data once secure keys have been established.