Which encryption category uses two keys, with one publicly shared and the other kept private?

Which encryption category uses two keys, with one publicly shared and the other kept private?

• A. Asymmetric encryption
• B. Symmetric Encryption
• C. One Time Pad
• D. Font Code (Steganography)

Answer: (A)

Two-key systems use a public key that can be shared openly and a private key that is kept secret. This setup lets anyone encrypt a message with the publicly available key, but only the owner of the private key can decrypt it. That separation of keys makes it possible to distribute encryption capability without exposing a secret key in advance, which is essential for secure key exchange and digital signatures. In contrast, symmetric encryption relies on a single secret key shared by both parties, so securing that key in transit is a major concern. The one-time pad involves a key as long as the message and used only once, which is a different kind of secret-key approach and not a public/private pair. Steganography hides the existence of a message rather than using a two-key cryptographic process.

Two-key systems use a public key that can be shared openly and a private key that is kept secret. This setup lets anyone encrypt a message with the publicly available key, but only the owner of the private key can decrypt it. That separation of keys makes it possible to distribute encryption capability without exposing a secret key in advance, which is essential for secure key exchange and digital signatures.

In contrast, symmetric encryption relies on a single secret key shared by both parties, so securing that key in transit is a major concern. The one-time pad involves a key as long as the message and used only once, which is a different kind of secret-key approach and not a public/private pair. Steganography hides the existence of a message rather than using a two-key cryptographic process.