Electronic transaction system
First Claim
1. An electronic transaction system for electronically sending and receiving digital signatures concerning a transaction message M between a first terminal for a first transacting party and a second terminal for a second transacting party, comprising:
- A. in said first terminal;
first means for generating a Hash total h'"'"'(M) of the transaction message M derived by compression-encoding said transaction message M and a Hash total h(M) different from said Hash total h'"'"'(M);
second means for preparing a digital signature T(A) by encoding data including at least first data containing the Hash total h'"'"'(M) and a first certificate not containing the transaction message M by using a secret key of the first transacting party, based on a public key cryptograph system;
third means coupled to the output of said second means for sending the prepared digital signature T(A) from said first terminal to said second terminal;
B. in said second terminal;
fourth means for preparing a digital signature S(B) by encoding data including at least second data containing the Hash total h(M) different from the Hash total h'"'"'(M) and a second certificate not containing the transaction message M by using a secret key of the second transacting party, based on said public key cryptograph system;
fifth means coupled to the output of said fourth means for sending the digital signature S(B) from said second terminal to said first terminal; and
C. in said first terminal;
sixth means responsive to reception of the digital signature S(B) from said second terminal for encoding data including at least third data containing the Hash total h(M) and a first certificate not containing the transaction message M by using the secret key of the first transacting party, based on said public key cryptograph system to obtain a digital signature S(A) and for sending the digital signature S(A) from said first terminal to said second terminal.
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Accused Products
Abstract
An electronic transaction in which in order to improve a reliability of message certification by digital signature and enable the use of the digital signature in a formal transaction in place of conventional signature or seal, the following procedures are implemented utilizing the fact that, in a public key cryptograph system represented by an RSA system, a first encoded message derived by encoding a first decoded message by using a public key of a first transacting party is equal to a second encoded message derived by encoding a second decoded message by using a public key of a second transacting party: (a) Check sender/receiver; (b) Add content certification function; (c) Double check the person by the possession of a secret key and the response by a terminal; (d) Add a grace period to the electronic seal; and (e) Send back a tally impression from the receiver to the sender.
153 Citations
4 Claims
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1. An electronic transaction system for electronically sending and receiving digital signatures concerning a transaction message M between a first terminal for a first transacting party and a second terminal for a second transacting party, comprising:
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A. in said first terminal; first means for generating a Hash total h'"'"'(M) of the transaction message M derived by compression-encoding said transaction message M and a Hash total h(M) different from said Hash total h'"'"'(M); second means for preparing a digital signature T(A) by encoding data including at least first data containing the Hash total h'"'"'(M) and a first certificate not containing the transaction message M by using a secret key of the first transacting party, based on a public key cryptograph system; third means coupled to the output of said second means for sending the prepared digital signature T(A) from said first terminal to said second terminal; B. in said second terminal; fourth means for preparing a digital signature S(B) by encoding data including at least second data containing the Hash total h(M) different from the Hash total h'"'"'(M) and a second certificate not containing the transaction message M by using a secret key of the second transacting party, based on said public key cryptograph system; fifth means coupled to the output of said fourth means for sending the digital signature S(B) from said second terminal to said first terminal; and C. in said first terminal; sixth means responsive to reception of the digital signature S(B) from said second terminal for encoding data including at least third data containing the Hash total h(M) and a first certificate not containing the transaction message M by using the secret key of the first transacting party, based on said public key cryptograph system to obtain a digital signature S(A) and for sending the digital signature S(A) from said first terminal to said second terminal.
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2. An electronic method for electronically sending and receiving digital signatures concerning a transaction message M between a first terminal for a first transacting party and a second terminal for a second transacting party, comprising the steps:
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A. in said first terminal; (1) generating a Hash total h'"'"'(M) of the transaction message M derived by compression-encoding said transaction message M and a Hash total h(M) different from said Hash total h'"'"'(M); (2) preparing a digital signature T(A) by encoding data including at least first data containing the Hash total h'"'"'(M) and a first certificate not containing the transaction message M by using a secret key of the first transacting party, based on a public key cryptograph system; (3) sending the prepared digital signature T(A) obtained in said step A(2) from said first terminal to said second terminal; B. in said second terminal; (1) preparing a digital signature S(B) by encoding data including at least second data containing the Hash total h(M) different from the Hash total h'"'"'(M) and a second certificate not containing the transaction message M by using a secret key of the second transacting party, based on the public key cryptograph scheme; (2) sending the digital signature S(B) obtained in said step B(1) from said second terminal to said first terminal; and C. in said first terminal; after receiving of the digital signature S(B) from said second terminal, encoding data including at least third data containing the Hash total h(M) and a first certificate not containing the transaction message M by using the secret key of the first transacting party, based on the public key cryptograph scheme to obtain a digital signature S(A), and sending the digital signature S(A) from said first terminal to said second terminal. - View Dependent Claims (3, 4)
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Specification