Digital-signed digital document exchange supporting method and information processor
First Claim
1. An information processor for supporting an exchange of a digital-signed digital document, the processor comprising:
- communication means connected to a network; and
processing means for, when the communication means receives a sign request including a first digital document from a first computer on the network, canonicalizing the first digital document by a method of implementing a canonicalization process, calculating a digest value of the canonicalized first digital document, and causing the communication means to output the digest value to the first computer,wherein the processing means is further adapted to perform the steps of;
when the communication means receives a sign request including a second digital document from a second computer on the network, canonicalizing the second digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized second digital document, and causing the communication means to output the digest value to the second computer, andwhen the communication means receives from one of the first and second computers on the network a validation request including a public key for validating a digital document with a digital sign and the digital document with the digital sign has been received from the other one of the first and second computers, canonicalizing the digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized digital document, comparing a value obtained by decrypting the digital sign with the public key and the calculated digest value, and causing the communication means output the result of the comparison to the computer which sent the validation request.
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Accused Products
Abstract
In response to a sign request including a digital document from a document-creating device 10, a digital-signed-document exchange supporting server 30 canonicalizes the digital document, calculates a digest value thereof, and returns the digest value to the document creating device. When the document-creating device transmits a digital sign created by encrypting the digest value to the digital-signed-digital document exchange-supporting server 30, the server 30 creates a digital-signed document from the digital sign and the digital document, and returns the document to the document-creating device. On the other hand, in response to a validation request including a digital-signed-digital document and a public key from a sign validating device 20, the server 30 compares a value resulting from the decryption of the digital sign with the public key and a digest value of the digital document canonicalized and returns the result to the sign validating device.
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Citations
9 Claims
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1. An information processor for supporting an exchange of a digital-signed digital document, the processor comprising:
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communication means connected to a network; and processing means for, when the communication means receives a sign request including a first digital document from a first computer on the network, canonicalizing the first digital document by a method of implementing a canonicalization process, calculating a digest value of the canonicalized first digital document, and causing the communication means to output the digest value to the first computer, wherein the processing means is further adapted to perform the steps of; when the communication means receives a sign request including a second digital document from a second computer on the network, canonicalizing the second digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized second digital document, and causing the communication means to output the digest value to the second computer, and when the communication means receives from one of the first and second computers on the network a validation request including a public key for validating a digital document with a digital sign and the digital document with the digital sign has been received from the other one of the first and second computers, canonicalizing the digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized digital document, comparing a value obtained by decrypting the digital sign with the public key and the calculated digest value, and causing the communication means output the result of the comparison to the computer which sent the validation request. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A digital-signed digital document exchange supporting method in which a server having communication means connecting to a network and processing means supports an exchange of a digital document with a digital sign on the network in calculating a digest value of a digital document, the method comprising the steps of:
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when the communication means receives a sign request including a first digital document from a first computer on the network, canonicalizing the first digital document by a method of implementing a canonicalization process, calculating a digest value of the canonicalized first digital document, and causing the communication means to output the digest value to the first computer, when the communication means receives a sign request including a second digital document from a second computer on the network, canonicalizing the second digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized second digital document, and causing the communication means to output the digest value to the second computer, and when the communication means receives from one of the first and second computers on the network a validation request including a public key for validating a digital document with a digital sign and the digital document with the digital sign has been received from the other one of the first and second computers, canonicalizing the digital document by the same method of implementing the canonicalization process, calculating a digest value of the canonicalized digital document, comparing a value obtained by decrypting the digital sign with the public key and the calculated digest value, and causing the communication means to output the result of the comparison to the computer which sent the validation request. - View Dependent Claims (8, 9)
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Specification