摘要 |
1,178,028. Digital transmission systems. INTERNATIONAL STANDARD ELECTRIC CORP. 16 June, 1967 [17 June, 1966], No. 27792/67. Heading H4P. A ciphering and deciphering system identical to that described in Specification 1,178,026 is described. The claims are directed to the conversion of certain function signals (e.g. Figure Shift) to other function signals prior to ciphering and following deciphering. |