| 摘要 |
PROBLEM TO BE SOLVED: To secure full security by avoiding the risk of data leakage in data decipherment, even when the access right to the data which is access restricted by encryption is transferred to another person. SOLUTION: A terminal 1a enciphers data S by using (a)'s secret key R to generate enciphered data A=S*R, stores it, and transmits the enciphered data A to a terminal 1b. The terminal 1b, when it receives the enciphered data A, enciphers the enciphered data A by using (b)'s secret key R', generates enciphered data A'=A*R', and transmits the enciphered data A' to the terminal 1a. The terminal 1a, when it receives the enciphered data A', further enciphers the enciphered data A' by using the (a)'s secret key R, generates enciphered data A"=A'*R, and transmits the enciphered data A", from the terminal 1a to the terminal 1b. Thus, in the terminal 1b, the received enciphered data A" is deciphered by using (b)'s secret key to obtain the data S. COPYRIGHT: (C)2006,JPO&NCIPI
|
