What describes public-key encryption?

• A. It uses a single key for both encryption and decryption
• B. It involves two different keys for the encryption process
• C. It is used primarily for decrypting data
• D. It can only encrypt small amounts of data

Answer: (B)

Public-key encryption is characterized by the use of two distinct keys: a public key and a private key. The public key is utilized for the encryption of data, allowing anyone to encrypt information that can only be decrypted by the corresponding private key, which is kept secret by the owner. This dual-key mechanism is fundamental to the security framework of public-key cryptography, as it enables secure communication between parties without the need to share a single encryption key.

The public key can be widely distributed, while the private key is securely held by the user, which mitigates the risk of key compromise during data transmission. This separation of keys not only enhances security but also supports various applications, such as digital signatures and secure email communication.

In contrast, other methods of encryption, such as symmetric encryption, rely on a single key for both encryption and decryption, making them less secure for transmitting sensitive information over untrusted networks. This is why the idea of utilizing two different keys is a fundamental aspect of public-key encryption, with its advantages becoming increasingly essential in the realm of information security.