Encrypted text verification system, method, and recording medium

Patent metadata

Field	Value
Publication number	US-10484182-B2
Application number	US-201515524151-A
Country	US
Kind code	B2
Filing date	Oct 26, 2015
Priority date	Nov 5, 2014
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

In a data registration phase, encrypted data is calculated by encrypting input data to be concealed by using a secret key, registration data is generated based on the encrypted data and a 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, the registration template stored in the storage unit and the data verifying request are 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.

First claim

The invention claimed is:

1. An encrypted text verification system, comprising: a registration data generation device; a storage device; a data verifying request device; and a data verifying determination device,
wherein the registration data generation device includes:
a key generation circuitry configured to generate a secret key and a verification key from a security parameter;
an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using the secret key; and
a registration data generation circuitry configured to generate registration data based on the encrypted data and the verification key;
wherein the storage device is configured to store the registration data generated by the registration data generation device as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data;
wherein the data verifying request device includes a data verifying request generation circuitry configured to generate a data verifying request in which input data to be verified has been encrypted by using a random number;
wherein the data verifying determination device includes:
a registration data reception circuitry configured to receive the registration template stored in the storage device;
a data verifying request reception circuitry configured to receive the data verifying request from the data verifying request device;
a data verifying determination circuitry configured to verify the registration template stored in the storage circuitry and the data verifying request to produce a determined result; and
a verified result generation circuitry configured to produce a verified result including a part or all of the registration template corresponding to the determined result,
wherein the data verifying request device further includes:
a verified result reception circuitry configured to receive the verified result from the data verifying determining device; and
a data restoration circuitry configured to restore data based on the verified result to produce a restored result.

2. The encrypted text verification system according to claim 1 ,
wherein the encryption circuitry is configured to calculate the encrypted data by taking an exclusive OR between the input data to be concealed and an error-correcting code generated by performing error-correction coding on the secret key, and
wherein the data verifying request generation circuitry is configured to generate the data verifying request by taking an exclusive OR between the input data to be verified and an error-correcting code obtained by performing error-correction coding on the random number.

3. The encrypted text verification system according to claim 2 , wherein the data verifying determination circuitry is configured to produce the determined result by performing error-correction decoding on an exclusive OR between the data verifying request and the encrypted data included in the registration template.

4. The encrypted text verification system according to claim 3 , wherein the verified result generation circuitry is configured to produce, as the verified result, a result obtained by adding to the determined result the verification key included in the registration template corresponding to the determined result.

5. The encrypted text verification system according to claim 4 , wherein the data restoration circuitry is configured to obtain the restored result by calculating an exclusive OR between the random number and the determined result included in the verified result, and to verify the restored result by using the verification key.

6. The encrypted text verification system according to claim 3 , wherein the verified result generation circuitry is configured to produce, as the verified result, the encrypted data included in the registration template corresponding to the determined result.

7. The encrypted text verification system according to claim 6 , wherein the data restoration circuitry is configured to obtain the restored result by performing error-correction decoding on an exclusive OR between the verified result and the input data to be verified.

8. An encrypted text verification system, comprising: a registration data generation device; a storage device; a data verifying request device; a first data verifying determination device; and a second data verifying determination device,
wherein the registration data generation device includes:
a key generation circuitry configured to generate a signature key and a verification key from a security parameter;
an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using the signature key; and
a registration data generation circuitry configured to generate registration data based on the encrypted data and the verification key;
wherein the storage device is configured to store the registration data generated by the registration data generation device as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data;
wherein the data verifying request device includes a first data verifying request generation circuitry configured to generate a first data verifying request in which input data to be verified has been encrypted by using a random number;
wherein the first data verifying determination device includes:
a registration data reception circuitry configured to receive the registration template from the storage device;
a first data verifying request reception circuitry configured to receive the first data verifying request from the data verifying request device;
a first data verifying determination circuitry configured to verify the registration template stored in the storage circuitry and the first data verifying request to produce a determined result;
a first verified result generation circuitry 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;
wherein the data verifying request device further includes:
a first verified result reception circuitry configured to receive the first verified result from the first data verifying determination device;
a decryption circuitry configured to decrypt the first verified result to produce a decrypted result; and
a second data verifying request generation circuitry configured to generate a second data verifying request based on the decrypted result and the message included in the first verified result;
wherein the second data verifying determination device includes:
a registration data reception circuitry configured to receive the registration template from the storage device;
a second data verifying request reception circuitry configured to receive the second data verifying request from the data verifying request device;
a second data verifying determination circuitry 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
a second verified result generation circuitry configured to generate, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination.

9. The encrypted text verification system according to claim 8 ,
wherein the encryption circuitry is configured to calculate the encrypted data by taking an exclusive OR between the input data to be concealed and an error-correcting code generated by performing error-correction coding on the signature key, and
wherein the first data verifying request generat

Assignees

• Nec Corp
• Obana Satoshi

Inventors

• Isshiki Toshiyuki
• Mori Kengo
• Araki Toshinori
• Obana Satoshi

Classifications

• H04L9/14

  using a plurality of keys or algorithms · CPC title

• H04L2209/12

  Details relating to cryptographic hardware or logic circuitry · CPC title

• G09C1/00

  Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system (cryptographic typewriters G09C3/00) · CPC title

• H04L9/30

  Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy · CPC title

• H03M13/152

  Bose-Chaudhuri-Hocquenghem [BCH] codes · CPC title