| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for the encryption of data transfer in a data transfer system divided into functional layers so that transferred data are in a data frame mode and that a data frame structure can be different for each of different layers. SOLUTION: There is provided a method for the encryption of information transferred between data transfer devices (MS, SGSN) in a data communication system wherein one or more data frames are created from one or more data packets formed of information by an application. The data frame comprises at least a header field and a data field. In the method, at least some part of the data packets is ciphered by using a ciphering key (Kc). To the data frames, synchronization data (COUNT) are attached, the value of which is changed at least at the transmission of each data frame. COPYRIGHT: (C)2006,JPO&NCIPI |
