| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of securing an IC card in order to prevent it from becoming detrimental, the IC card being a memory medium such as USIM cards used in communication terminals. <P>SOLUTION: When a USIM card securing means 104 issues a collation command three times in succession, using an unauthorized PIN value, a USIM card 100 turns to a block mode disabling access to the card. When the card securing means 104 further issues an UNBLOCK PIN command ten times in succession, the card 100 turns to a mode disabling a user to cancel the block mode. These operations cause the card 100 to turn to the block mode disabling the read/write in a file, i.e., a request of access to a PIN, thus preventing the USIM card 100 from being illegally used. <P>COPYRIGHT: (C)2003,JPO |
