Cisco Cyber Security Practice Exam

What is the role of a public key in asymmetric encryption?

1. To decrypt messages

2. To encrypt messages

3. To generate hashes

4. To manage keys

The correct answer is: To encrypt messages

In asymmetric encryption, the public key plays a crucial role in the encryption process. It is used to encrypt messages that can only be decrypted by the corresponding private key, which is kept secret by the intended recipient. This mechanism ensures that anyone can send a secure message to the recipient by utilizing their public key, knowing that only the holder of the private key can decrypt and read that message. The design of asymmetric encryption relies on a key pair—one public and one private. The public key is distributed openly and can be shared freely, while the private key must remain confidential. This system enables secure communications over potentially insecure channels, as it protects the content of the messages against unauthorized access. The other options relate to different aspects of cryptography. For example, the decryption of messages involves the private key and not the public key. Hash generation typically employs a hashing algorithm rather than public keys. Key management might involve both keys but does not specifically pertain to the function of the public key in the encryption process. Thus, the function of the public key is primarily centered around its use for encrypting messages, ensuring that sensitive information is kept secure during transmission.