| 摘要 |
In this process for calling only pre-programmed telephone numbers, when access or a line is requested, the telephone number is transmitted from the telephone to the card, which checks whether the number may be called and, if so, generates a signature by means of a secret algorithm from said number and a changing code given by the network. This is transmitted together with the number to the network which releases the selected number via the card after checking the signature. |
