| 摘要 |
PROBLEM TO BE SOLVED: To deposit part of received electronic cash in a bank while keeping the privacy. SOLUTION: Electronic cash in an amount (x) is paid to an issuing organization device 100, identification information IdU is blind processed (430) with an open key in an amount (y) (y<=x), and the process results Z and (y) are sent to the device 100, which signs Z with the secret key of (y) and sends the sign Cwi to a device 400; and the device 400 unblind processes Cwi to obtain the sign Cw of the device 100 for IdU (440) and sends Cw, IdU, (y) to the bank, where Cw is verified and the account of IdU is increased in amount when Cw is acceptable. |
