Ciphered

Ciphered is the past participle of encipher or cipher, used to describe information that has been transformed by a cipher into ciphertext. In cryptography, ciphering is the process of applying a deterministic algorithm and a key to convert plaintext into ciphertext, which is unreadable without the corresponding key. The reverse process, deciphering or decryption, restores the original message.

Etymology and usage: The term derives from cipher, historically referring to a method of writing or a secret figure. The verb encipher emerged to denote converting plaintext to ciphertext. In modern practice, ciphered may be used interchangeably with encrypted, though some prefer encipherment to describe the process and encryption to describe the state.

Historical context: Throughout history, ciphered messages enabled confidential communication. Classical methods include substitution ciphers, where symbols replace letters, and transposition ciphers, where symbols are rearranged. In the 20th century, cryptographic practice evolved toward standardized algorithms and key-based security.

Modern context: Contemporary ciphering uses algorithms executed by computer systems. Symmetric-key ciphers, such as AES, use the same key for encryption and decryption, while asymmetric systems, such as RSA, use a public/private key pair. The term ciphered can describe data stored on media or transmitted over networks when it is in ciphertext form; strong ciphered data is designed to be unreadable without the key.

See also: encryption, encipherment, decipherment, ciphertext, cryptography.