| 摘要 |
PURPOSE:To eliminate the need for the change of a key pattern which is supplied to each terminal, by providing a code converter and a cipher device. CONSTITUTION:A code converter 101 performs code conversion of RN for both terminals T1 and T2 to obtain a result -NR. This -NR is sent to a cipher device 103 by a selector 102 to undergo a code conversion to be turned into EMK1(-RN) with T1 and EMK2(-RN) with T2 respectively. The terminals T1 and T2 send these outputs to a terminal of the remote side, respectively. Thus T1 and T2 receive EMK2(-RN) and EMK1(-RN) respectively. Each terminal supplies the received code to an input terminal 105, and then the code is ciphered again by the device 103. As a result, the terminals T1 and T2 obtain EMK1 [EMK2(-RN)] and EMK2[EMK1(-RN)], respectively, to use them as a common secret key. |
