Method for fragmenting data packet including bio information and method for authenticating fragmented data packet including bio information

A fragmenting method of a data packet inserting bio information and an authentication method of a fragmented data packet are provided to improve the reliability of the authentication by performing the authentication about a user. A first digest value about the authentication of the data packet is calculated to a first cryptographic key by using bio information by a server(300). The data packet is fragmented to a plurality of packets in case the fragmentation of data packet is requested(340). A second digest value for the authentication of each packet is calculated to the second cryptographic key especially generated with each packet(350). The second digest value of the first packet and the first digest value is inserted into domain between the IP header of the first packet which is the original packet and the TCP header among the fragmented packet(360). The third digest value is produced from the second digest value of second packets and it inserts into the header area of the second packet(380).