What term means encrypted, unreadable data?

• A. Ciphertext
• B. Plaintext
• C. Key
• D. Cipher

Answer: (A)

Ciphertext is the encrypted, unreadable form of data. When you take readable information (plaintext) and apply an encryption algorithm with a key, you produce ciphertext. It’s meant to be unintelligible without the correct key, protecting confidentiality. To recover the original message, the appropriate key is used to decrypt the ciphertext back into plaintext. The other terms have different roles: plaintext is the readable data; a key is the secret value that enables the transformation; a cipher is the method or algorithm used for encryption and decryption.