Which statement about the private key in public-key cryptography is true?

• A. Public Key
• B. Private Key
• C. Symmetric Cryptography
• D. One-Way Function

Answer: (B)

Public-key cryptography relies on a key pair: a publicly shareable key and a secret private key. The private key stays confidential and is used to decrypt data that was encrypted with the public key, and to create digital signatures that others verify using the public key. This separation lets you receive encrypted messages securely and prove ownership or authorship of data with a signature. The public key is the one you can share freely, symmetric cryptography uses the same key for encryption and decryption, and a one-way function is a general cryptographic property rather than a description of the private key itself.