| 摘要 |
PROBLEM TO BE SOLVED: To prevent an inputted identification(ID) number from being easily predicted from input operation by successively allocating random numbers to symbols to be displayed on an LCD in a key entry area and changing the order of random numbers in each insertion of an IC card by a user. SOLUTION: When a user inserts an IC card into an IC card reader part 11 on a portable terminal, a card detection sensor sends a card detection signal to a CPU 2, which communicates with the IC card by the card reader part 11 and displays a message demanding the input of a user's ID number on an LCD 5. The user inputs his (or her) own ID number by touching a number button area displayed on the LCD screen with a finger. Symbols to be displayed on the LCD 5 are successively changed by using random numbers and the order of displayed symbols is changed in each insertion of the IC card. Consequently the inputted ID number is not known by a third person even when the input operation of the ID number is looked at by the third person. |
