Patent ID: 7895450

Claim:
A data management method comprising: receiving an encryption key and a security code in a server from a first user terminal, the encryption key being stored in the first user terminal and the security code being input by a user; receiving, a security code from the first user terminal; encrypting the encryption key in the server, said encrypting the encryption key is performed using the security code sent from the first user terminal; issuing a registration code for the encryption key; storing the encrypted encryption key and the registration code in association with each other in the server; sending the registration code to the first user terminal; displaying the registration code to the user on the first user terminal; erasing the encryption key from the first user terminal; inputting the registration code and the security code on a second user terminal; receiving the registration code and the security code in the server from the second user terminal; decrypting the stored and encrypted encryption key in the server using the security code sent from the second user terminal, when the registration code sent from the second user terminal is identical to the stored registration code, sending the decrypted encryption key to the second user terminal; and storing the decrypted encryption key on the second user terminal.