The contract generating module 110 is used for generating a proposition contract by the first party.
The encryption module 120 is used for encrypting the proposition contract 31.
The sending module 130 is used for sending the encrypted proposition contract 31 to the client 20.
The second party obtains the proposition contract 31 by decrypting the encrypted proposition contract 31, electronically signs the proposition contract 31 via the client 20, thereby yielding an endorsed contract, and returns the endorsed contract to the server 10.
The receiving module 140 is used for receiving the endorsed contract 32 sent from the client 20.
The validating module 150 is used for validating whether the terms and conditions of the endorsed contract 32 (not including the signature of the second party) are the same as the terms and conditions of the proposition contract 31.
The signing module 160 is used for electronically signing the endorsed contract 32 by the first party if the terms and conditions of the endorsed contract 32 are the same as the terms and conditions of the proposition contract 31, thereby yielding an effective contract 33.
The validating module 150 is further configured for validating whether the digital signature of the second party in the endorsed contract 32 and the digital signature of the first party in the effective contract 33 are valid signatures according to validating digital signatures stored in the server.
In step S11, the contract generating module 110 generates a proposition contract 31 by the first party via the server 10.
In step S12, the encryption module 120 encrypts the proposition contract 31.
In step S13, the sending module 130 sends the encrypted proposition contract 31 to the client 20.
In step S14, the second party obtains the proposition contract 31 by decrypting the encrypted proposition contract 31, electronically signs the proposition contract 31 via the client 20, thereby yielding an endorsed contracted 32, and returns the endorsed contract 32 to the server 10.
In step S15, the receiving module 140 receives the endorsed contract 32.
In step S16, the validating module 150 validates whether the terms and conditions of the endorsed contract 32 (not including the signature of the second party) are the same as the terms and conditions of the proposition contract 31.
In step S17, if the terms and conditions of the endorsed contract 32 are the same as the terms and conditions of the proposition contract 31, the validating module 150 validates whether the digital signature of the second party in the endorsed contract 32 is a valid signature according to a validating digital signature of the second party stored in the server 10.
In step S18, if the signature of the second party in the endorsed contract 32 is a valid signature, the first party electronically signs the endorsed contract 32 through the signing module 160, thereby yielding an effective contract 33.
In step S19, the validating module 150 validates whether the digital signature of the first party in the effective contract 33 is a valid signature according to a validating digital signature of the first party stored in the server 10. If the signature of the first party in the effective contract 33 is a valid signature, the procedure ends; otherwise, the procedure returns to step S18.
If the terms and conditions of the endorsed contract 32 are not the same as the terms and conditions of the proposition contract 31 in step S16, the procedure returns to the step S13 described above.
If the signature of the second party in the endorsed contract 32 is not a valid signature in step S17, the procedure returns to the step S13 described above.
It should be emphasized that the above-described embodiments of the preferred embodiments, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described preferred embodiment(s) without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the above-described preferred embodiment(s) and protected by the following claims.
Number | Date | Country | Kind |
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200610200787.1 | Aug 2006 | CN | national |