Patent ID: 11917074
Assignee: SECUVE CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 25:
26. In an authentication server capable of being interfaced to a user device of a signer and an electronic document device of an electronic document provider, an electronic signature authentication method based on biometric information comprising:
receiving an electronic file to be verified which combines a second encryption data generated by encrypting the hash value calculated by the user device for the electronic document received by the user device and the first electronic signature value for the electronic document with a public key of the authentication server, a third encryption data generated by encrypting the handwritten signature for final document confirmation, a hash value of the handwritten signature for final document confirmation, and the second electronic signature value for the handwritten signature for final document confirmation with the public key of the authentication server, a fourth encryption data generated by encrypting the at least one handwritten signature for document confirmation inserted into the electronic document, the hash value of the at least one handwritten signature for document confirmation, and a third electronic signature value for the handwritten signature for document confirmation with the public key of the authentication server, and a fifth encryption data generated by encrypting the hash value calculated by the electronic document device for the electronic document and a fourth electronic signature value for the electronic document with the public key of the authentication server;
extracting the hash value calculated by the user device for the electronic document received by the user device, the first electronic signature value for the electronic document, the handwritten signature for final document confirmation, the hash value of the handwritten signature for final document confirmation, the second electronic signature value for the handwritten signature for final document confirmation, the at least one handwritten signature for document confirmation inserted into the electronic document, the hash value of the at least one handwritten signature for document confirmation, the third electronic signature value for at least one the handwritten signature for document confirmation, the hash value calculated by the electronic document device for the electronic document, and a fourth electronic signature value for the electronic document by decrypting the second through fifth encryption data combined to the electronic file to be verified with a private key of the authentication server;
calculating a hash value of an electronic document combined in the electronic file to be verified and verifying integrity of the electronic document assuring that the electronic document extracted from the electronic file to be verified is the electronic document generated by the electronic document provider by comparing the hash value calculated by the authentication server for the electronic document extracted from the electronic file to be verified, the hash value extracted by decrypting the fourth electronic signature value with the public key of the electronic document provider, and the hash value calculated by the electronic document device for the electronic document and extracted from the fifth encryption data with each other;
calculating a hash value of the at least one handwritten signature for document confirmation extracted from the electronic file to be verified and verifying integrity of the at least one handwritten signature for document confirmation included in the electronic file to be verified by comparing the hash value calculated, by the authentication server, for the at least one handwritten signature for document confirmation extracted from the electronic file to be verified, the hash value of the at least one handwritten signature for document confirmation extracted by decrypting the third electronic signature value with the public key of the signer, and the hash value calculated by the user device for the at least one handwritten signature for document confirmation and extracted from the fourth encryption data with each other;
calculating a hash value of the handwritten signature for final document confirmation extracted from the electronic file to be verified and verifying integrity of the handwritten signature for final document confirmation included in the electronic file to be verified by comparing the hash value calculated, by the authentication server, for the handwritten signature for final document confirmation extracted from the electronic file to be verified, the hash value of the handwritten signature for final document confirmation extracted by decrypting the second electronic signature value with the public key of the signer, and the hash value of the handwritten signature for final document confirmation extracted from the third encryption data with each other; and
calculating a hash value of the electronic document extracted from the electronic file to be verified and verifying at least one of: non-repudiation of the electronic signature of the signer, non-repudiation of the electronic signature of the electronic document provider, consistency between the electronic document signed by the signer and the electronic document signed by the electronic document provider, and integrity of the electronic document by comparing the hash value calculated by the authentication server for the electronic document extracted from the electronic file to be verified, the hash value of the electronic document extracted by decrypting the first electronic signature value with the public key of the signer, the hash value calculated by the user device for the electronic document received by the user device, and the hash value calculated by the electronic document provider for the electronic document generated by the electronic document provider with each other.