Shop apparatus, purchaser apparatus, purchaser identity proving apparatus, and purchaser identity verifying apparatus

MODIFICATION OF EMBODIMENT 1

[0215] This embodiment can be applied to the access control system described in Jpn. Pat. Appln. KOKAI Publication No. 2004-054905 and the anonymous authentication system described in Jpn. Pat. Appln. KOKAI Publication No. 2004-320562. When the embodiment is applied to the systems of these two publications, an ID capable of uniquely identifying a service request may be used, instead of the above-mentioned order ID. For example, if the length of challenge is sufficiently long in the anonymous authentication system described in Jpn. Pat. Appln. KOKAI Publication No. 2004-320562, a challenge may be used.

[0216] As a method of selecting a requested order ID by the purchaser identity proving unit 37, a purchaser may explicitly select such, or the purchaser apparatus 30 may automatically select such.

[0217]For example, when a purchaser wants to make an inquiry about certain merchandise or a merchandise return request, the purchaser must select the method. On the ...

MODIFICATION OF EMBODIMENT 2

[0270], The first and second modifications and of the first embodiment can also be realized as modifications of this embodiment.

[0271] This embodiment can be modified to use zero knowledge proof of other systems, in addition to the zero knowledge proof of Definition 4 described in G. Ateniese, J. Camenisch, M. Joye and G. Tsudik, “A Practical and Provably Secure Coalition-Resistant Group Signature Scheme”, CRYPTO 2000, LNCS 1880, Springer-Verlag, pp. 255-270, 2000.

[0272] This embodiment can be modified to use a traceable signature instead of a group signature, and to use claiming in a traceable signature instead of zero knowledge proof (e.g., refer to A. Kiayias, Y. Tsioumis, M. Young, “Traceable Signatures”, EUROCRPT 2004, lncs 3027, Springer-Verlag, pp. 571-589, 2004).

[0273] this embodiment dos not use a different value for each order as purchaser identity proving secret information, but can use a value common to all orders. In this case, values need...

MODIFICATION OF EMBODIMENT 3

[0309], The first and second modifications and of the first embodiment can also be realized as modifications of this embodiment.

[0310] This embodiment can be modified to use zero knowledge proof of other systems, in addition to the zero knowledge proof of Definition 5 described in G. Ateniese, J. Camenisch, M. Joye and G. Tsudik, “A Practical and Provably Secure Coalition-Resistant Group Signature Scheme”, CRYPTO 2000, LNCS 1880, Springer-Verlag, pp. 255-270, 2000.

[0311] This embodiment can use purchaser identity proving secret information common to all orders. In this case, it is unnecessary to manage a value for each order, and the value may be managed just like a member secret key.

EMBODIMENT 4

[0312]FIG. 19 is a schematic diagram showing the configuration of an anonymous order system according to a fourth embodiment of the invention. FIG. 20 and FIG. 21 are schematic diagrams showing a storage unit for a purchaser, and a purchaser identity proving se...