# US 10,503,915 B2 · Encrypted text verification system, method and recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,503,915 B2 - Document ID: US10503915B2 - Status: Granted - Kind: B2 - Application number: 15/553,264 - Filed: 2016-01-27 - Published: 2018-08-23 - Granted: 2019-12-10 - Earliest claimed: 2015-02-24 - Assignees: NEC Corporation; Satoshi Obana - Applicants: NEC Corporation; Satoshi Obana - Inventors: Toshiyuki Isshiki; Kengo Mori; Toshinori Araki; Satoshi Obana - Web page: https://patentgrep.com/patent/US10503915B2 ## CPC - G06F 21/602: {Providing cryptographic facilities or services} - G06F 21/32: using biometric data, e.g. fingerprints, iris scans or voiceprints - H04L 9/0861: {Generation of secret information including derivation or calculation of cryptographic keys or passwords} - H04L 9/0869: {involving random numbers or seeds} - H04L 9/14: using a plurality of keys or algorithms - H04L 9/3231: {Biological data, e.g. fingerprint, voice or retina (network architectures or network communication protocols for supporting authentication of entities using biometrical features in a packet data network H04L63/0861)} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In a system with registration data, in a data registration phase, encrypted data is calculated by encrypting input data to be concealed by using a secret key and secret information, registration data is generated based on the encrypted data and verification key, and the registration data is stored as a registration template in a storage unit together with an identifier for uniquely identifying the registration data. In an encrypted text verification phase, a data verifying request is generated in which input data to be verified has been encrypted by using a random number and secret information, the registration template stored in the storage unit and the data verifying request are matched verified to produce a determined result, a verified result including a part or all of the registration template corresponding to the determined result is produced, and data is restored based on the verified result to produce a restored result. ## Claims ### Claim 1 An encrypted text verification system, comprising: an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using a signing key and secret information; registration data generator hardware configured to generate registration data based on the encrypted data and a verification key; a storage device configured to store the registration data as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data; first data verifying request generator hardware configured to generate a first data verifying request in which input data to be verified has been encrypted by using a random number and the secret information; first data verifying determiner hardware configured to verify the registration template stored in the storage circuitry and the first data verifying request to produce a determined result; first verified result generator hardware configured to generate, as a first verified result, a combination of a message that has been randomly selected and a part or all of the registration template corresponding to the determined result; a decryption circuitry configured to decrypt the first verified result to produce a decrypted result; second data verifying request generator hardware configured to generate a second data verifying request based on the decrypted result and the message included in the first verified result; second data verifying determiner hardware configured to generate a second data verifying determination based on the second data verifying request and the registration data of the registration template recorded in the storage circuitry; and second verified result generator hardware configured to generate, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination. ### Claim 2 (depends on 1) A biometric authentication system, comprising the encrypted text verification system of claim 1, the input data to be concealed and the input data to be verified comprising biological information, the biometric authentication system being configured to perform biometric authentication by determining whether or not the input data to be concealed and the input data to be verified are similar. ### Claim 3 (depends on 1) The encrypted text verification system according to claim 1, further including: key generator hardware configured to generate the signing key and the verification key based on a security parameter; and secret information generator hardware configured to generate the secret information from the security parameter. ### Claim 4 An encrypted text verification system, comprising: an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using a secret key and secret information; registration data generator hardware configured to generate registration data based on the encrypted data and a public key; a storage device configured to store the registration data as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data; first data verifying request generator hardware configured to generate a first data verifying request in which input data to be verified has been encrypted by using a random number and the secret information; first data verifying determiner hardware configured to verify the registration template stored in the storage circuitry and the first data verifying request to produce a determined result; first verified result generator hardware configured to generate, as a first verified result, a combination of a message that has been randomly selected and a part or all of the registration template corresponding to the determined result; a decryption circuitry configured to decrypt the first verified result to produce a decrypted result; second data verifying request generator hardware configured to generate a second data verifying request based on the decrypted result and the message included in the first verified result; second data verifying determiner hardware configured to generate a second data verifying determination based on the second data verifying request and the registration data of the registration template recorded in the storage circuitry; and second verified result generation generator hardware configured to generate, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination. ### Claim 5 (depends on 4) The encrypted text verification system according to claim 4, wherein the encryption circuitry is configured to calculate the encrypted data by taking an exclusive OR among an error-correcting code generated by performing error-correction coding on the signing key, the input data to be concealed, and the secret information, and wherein the first data verifying request generator hardware is configured to generate the first data verifying request by taking an exclusive OR among the input data to be verified, an error-correcting code obtained by performing error-correction coding on the random number, and the secret information. ### Claim 6 (depends on 5) The encrypted text verification system according to claim 5, wherein the first data verifying determiner hardware is configured to perform error-correction decoding on an exclusive OR between the first data verifying request and the encrypted data included in the registration data of the registration template, and to produce, as the determined result, a set of identifiers corresponding to the encrypted data for which a result is that decryption is not impossible. ### Claim 7 (depends on 6) The encrypted text verification system according to claim 6, wherein the first verified result generator hardware is configured to generate, as the first verified result, a combination of the message that has been randomly selected and the encrypted data included in the registration data of the registration template corresponding to the determined result. ### Claim 8 (depends on 7) The encrypted text verification system according to claim 7, wherein the decryption circuitry is configured to obtain the decrypted result by performing error-correction decoding on an exclusive OR between the input data to be verified and the encrypted data included in the first verified result. ### Claim 9 (depends on 6) The encrypted text verification system according to claim 6, wherein the second data verifying request generator hardware is configured to generate the second verifying request by signing and generating the decrypted result and the message included in the first verified result. ### Claim 10 (depends on 9) The encrypted text verification system according to claim 9, wherein the second data verifying determiner hardware is configured to sign and verify the second verifying request, the message, and the registration data of the registration template recorded in the storage circuitry, and to generate, as the second data verifying determination, a set of identifier numbers having a result indicating acceptance. ### Claim 11 (depends on 10) The encrypted text verification system according to claim 10, wherein the second verified result generator hardware is configured to generate, as the second verified result, an identifier of the registration data corresponding to the registration template corresponding to the second data verifying determination. ### Claim 12 (depends on 4) The encrypted text verification system according to claim 4, further including: key generator hardware configured to generate the secret key and the public key based on a security parameter; and secret information generator hardware configured to generate the secret information from the security parameter. ### Claim 13 (depends on 4) The encrypted text verification system according to claim 4, wherein the encryption circuitry is configured to calculate the encrypted data by taking an exclusive OR among an error-correcting code generated by performing error-correction coding on the secret key, the input data to be concealed, and the secret information, and wherein the first data verifying request generator hardware is configured to generate the first data verifying request by taking an exclusive OR among the input data to be verified, an error-correcting code obtained by performing error-correction coding on the random number, and the secret information. ### Claim 14 (depends on 13) The encrypted text verification system according to claim 13, wherein the first data verifying determiner hardware is configured to perform error-correction decoding on an exclusive OR between the first data verifying request and the encrypted data included in the registration data of the registration template, and to produce, as the determined result, a set of identifiers corresponding to the encrypted data for which a result is that decryption is not impossible. ### Claim 15 (depends on 14) The encrypted text verification system according to claim 14, wherein the first verified result generator hardware is configured to generate, as the first verified result, a combination of the message that has been randomly selected and the public key included in the registration data of the registration template corresponding to the determined result. ### Claim 16 (depends on 15) The encrypted text verification system according to claim 15, wherein the decryption circuitry is configured to obtain the decrypted result by performing error-correction decoding on an exclusive OR between the input data to be verified and the public key included in the first verified result. ### Claim 17 (depends on 14) The encrypted text verification system according to claim 14, wherein the second data verifying request generator hardware is configured to generate the second verifying request by encrypting the decrypted result and the message included in the first verified result. ### Claim 18 (depends on 17) The encrypted text verification system according to claim 17, wherein the second data verifying determiner hardware is configured to decrypt the second verifying request and the registration data of the registration template recorded in the storage circuitry, and to generate, as the second data verifying determination, a set of identifier numbers having a result indicating acceptance. ### Claim 19 (depends on 18) The encrypted text verification system according to claim 18, wherein the second verified result generator hardware is configured to generate, as the second verified result, an identifier of the registration data corresponding to the registration template corresponding to the second data verifying determination. ### Claim 20 A method of verifying encrypted text, the method comprising: a data registration procedure comprising: calculating, by a first client, encrypted data by encrypting input data to be concealed by using a signing key and secret information; generating, by the first client, registration data based on the encrypted data and a verification key; and storing, by a server, the registration data as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data; and an encrypted text verifying procedure comprising: generating, by a second client, a first data verifying request in which input data to be verified has been encrypted by using a random number and the secret information; verifying, by the server, the registration template stored in the storage circuitry and the first data verifying request to produce a determined result; producing, by the server, as a first verified result, a combination of a message that has been randomly selected and a part or all of the registration template corresponding to the determined result; decrypting, by the second client, the first verified result to produce a decrypted result; generating, by the second client, a second verifying request based on the decrypted result and the message included in the first verified result; generating, by the server, a second data verifying determination based on the second verifying request and the registration data of the registration template recorded in the storage unit; and producing, by the server, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination.