| 摘要 |
PURPOSE:To provide the IC card having a key signal which is safe in case of wiretapping by increasing the security of key data used by a satellite broadcast receiver, etc., to reset a scramble signal. CONSTITUTION:A 1st key 19 is ciphered with a 2nd key 21 into ciphered key data 20. Then the key data 20 are deciphered by deciphering algorithm 23 and recorded as a 3rd key 24 in a RAM 15 as a 2nd memory means. The RAM 15 as the 2nd memory means is a volatile memory, so when the IC card 11 is extracted from a card reader for the analysis of the key data, the 3rd key 24 recorded in the RAM 15 as the 2nd memory means is erased and the analysis is impossible. This IC card is therefore high in the security of the 3rd key 24 and safe against wiretapping. |
