| 摘要 |
PURPOSE:To decode the cryptography for a specific contracted device individually and safely by the remote control at the sender side by using an identification code so as to specify a receiver and applying ciphering and decoding to information of a key table or the like requiring to decode individual contract programs while applying individual remote control. CONSTITUTION:The equipment is provided with a cryptographic key generating means 2 generating plural cryptographic keys and respective index number of the key and a cryptographic key selection means 20 outputting one of generated cryptographic key and its index number. Moreover, a 1st cryptographic means 6 converting a plain sentence into a cryptographic sentence under the selected cryptographic key and a storage means 4 storing each identification code of one or plural receivers allowing the decoding are provided. Furthermore, a 2nd cryptographic means 5 ciphering the plural cryptographic key and their index numbers and generating a transmission key table under the identification code and a data transmission means 7 sending at least the cryptographic sentence and the index number of the cryptographic key used for ciphering are provided. Thus, the privacy call processing and ciphering with high safety without signal deterioration are applied and the operation of specific channel and specific receivers is controlled remotely from the sender side in response to the content of contract. |
