(ISC)2 Certified in Cybersecurity Practice Exam

Which algorithms use keypairs where each user has a public key and a private key?

1. Symmetric

2. Asymmetric

3. Linear

4. Polynomial

The correct answer is: Asymmetric

The correct answer is based on the fundamental principles of asymmetric cryptography, where each user possesses both a public and a private key. This keypair system facilitates secure communication, as the public key can be shared openly, allowing others to encrypt messages specifically for the key owner. However, only the corresponding private key can decrypt these messages, ensuring that sensitive information remains confidential. Asymmetric algorithms are pivotal in various security protocols, including securing email, enabling secure web browsing, and establishing secure VPN connections. This method contrasts sharply with symmetric algorithms, where a single shared key is utilized for both encryption and decryption, leading to potential key distribution challenges. The mention of linear and polynomial does not pertain to cryptographic algorithms in this context. Instead, these terms are associated with mathematical functions and complexity theory, which do not involve keypair systems like those in asymmetric cryptography. This distinction underscores why the answer identifies asymmetric algorithms as the correct choice.