WebCPC CPC COOPERATIVE PATENT CLASSIFICATION

G09C　CODING OR CIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHER PURPOSES INVOLVING THE NEED FOR SECRECY (secret transmission H04K; arrangements for secret telegraphic communication H04L 9/00)

G09C 1/00 Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a pre-determined system (cryptographic typewriters G09C 3/00)

G09C 1/02 ・by using a ciphering code in chart form

G09C 1/04 ・with sign carriers or indicators moved relative to one another to positions determined by a permutation code, or key, so as to indicate the appropriate corresponding clear or ciphered text

G09C 1/06 ・wherein elements corresponding to the sign making up the clear text are operatively connected with elements corresponding to the signs making up the ciphered text, the connections, during operation of the apparatus, being automatically and continuously permuted by a coding or key member

G09C 1/08 ・・the connections being mechanical

G09C 1/10 ・・the connections being electrical

G09C 1/12 ・・・comprising contact-bearing permutation discs

G09C 1/14 ・・involving removable or interchangeable coding numbers, e.g. master tapes, punched cards

G09C 3/00 Typewriters for ciphering or deciphering cryptographic text (marking record carriers G06K)

G09C 3/02 ・with auxiliary keys or keyboards acting on the original key or keyboards

G09C 3/04 ・wherein the operative connections between the keys and the type-bars are automatically and continuously permuted, during operation, by a coding or key member

G09C 3/06 ・・the connections being mechanical

G09C 3/08 ・・the connections being electrical

G09C 3/10 ・・involving removable or interchangeable coding members, e.g. master tapes, punched cards

G09C 5/00 Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages