Which type of encryption uses a public key and a private key?

• A. Public Key
• B. Private Key
• C. Asymmetric Cryptography
• D. Symmetric Cryptography

Answer: (C)

Two-key systems are at work here. In asymmetric cryptography, you have a key pair: a public key that can be shared openly and a private key that stays secret. Encrypting with the public key means only the private key holder can decrypt, enabling secure communication without pre-sharing a secret. You can also sign with your private key and others can verify the signature with your public key, proving who sent it. This is different from symmetric cryptography, which relies on a single shared key for both encryption and decryption. So the type that uses both a public key and a private key is asymmetric cryptography.