CIPHERING OR DECIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHER PURPOSES INVOLVING THE NEED FOR SECRECY

Description

G09C covers mechanical, electromechanical, and electronic apparatus designed to encrypt, decrypt, or otherwise process information requiring confidentiality. This includes rotor-based cipher machines (such as Enigma-type devices), electromechanical encryption systems, and early electronic cryptographic equipment used for secure communication. The classification encompasses both the hardware apparatus itself and the functional mechanisms for generating, applying, or reversing cryptographic transformations. Related cryptographic algorithms, mathematical methods, or software-based encryption systems are typically classified elsewhere (e.g., H04L for digital encryption in telecommunications).