Which type of algorithm uses public and private keys?

Which type of algorithm uses public and private keys?

• A. Asymmetric Algorithm
• B. Symmetric Encryption
• C. Key Length
• D. Hashing

Answer: (A)

This is about public-key cryptography, where two keys are used for different roles. The best answer is an asymmetric algorithm. In asymmetric cryptography, you have a public key that can be shared openly and a private key that is kept secret. You can encrypt data with the public key so only the private key holder can decrypt it, or you can sign with the private key and let others verify the signature with the public key. This contrasts with symmetric encryption, which uses a single shared secret key for both encryption and decryption, requiring secure key delivery. Hashing is not a key-based process at all—it produces a fixed digest for integrity and authentication, not encryption. Key length is a property of the algorithm’s security strength, not the type of algorithm itself.

This is about public-key cryptography, where two keys are used for different roles. The best answer is an asymmetric algorithm. In asymmetric cryptography, you have a public key that can be shared openly and a private key that is kept secret. You can encrypt data with the public key so only the private key holder can decrypt it, or you can sign with the private key and let others verify the signature with the public key. This contrasts with symmetric encryption, which uses a single shared secret key for both encryption and decryption, requiring secure key delivery. Hashing is not a key-based process at all—it produces a fixed digest for integrity and authentication, not encryption. Key length is a property of the algorithm’s security strength, not the type of algorithm itself.