ENCRYPTED STATISTICAL PROCESSING SYSTEM, DEVICE, METHOD, AND PROGRAM

• US 20140115321A1
• Filed: 05/30/2012
• Published: 04/24/2014
• Est. Priority Date: 06/10/2011
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Isshiki, Toshiyuki
• Granted Patent: US 9,548,861 B2
• Time in Patent Office: Days
• US Class Current: 713/153
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations network architectures or network communication protocols using hop-by-hop encryption H04L63/0464
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04L 9/30 Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy
• CPC Class Codes: H04L 9/3073 involving pairings, e.g. identity based encryption [IBE], bilinear mappings or bilinear pairings, e.g. Weil or Tate pairing

Abstract

A service provider device includes key generation means, which generates a service public key for encrypting data and a secret key, and proxy key generation means, which inputs the service public key and the secret key and generates a proxy key. A data registration device includes encrypted data generation means, which generates encrypted data upon input of the service public key and data, and stores the generated encrypted data in a database. Proxy devices each includes encrypted portion statistical data generation means, which generates encrypted portion statistical data upon input of the proxy key with respect to the encrypted data stored in the database. An integrated data generation device includes encrypted statistical data generation means, which inputs the encrypted portion statistical data from each of the proxy devices, generates encrypted statistical data, and stores the generated encrypted statistical data in an integrated data storage device.

Claims

1. An encrypted statistical processing system comprising:

a plurality of service provider devices;

a data registration device;

a database;

a plurality of proxy devices;

an integrated data generation device; and

an integrated data storage device;

wherein the service provider devices each include

a key generation unit, which generates a service public key for encrypting data and a secret key corresponding to the service public key, and

a proxy key generation unit, which generates a proxy key upon input of the service public key and the secret key;

wherein the data registration device includes an encrypted data generation unit, which generates encrypted data upon input of the service public key and predetermined data;

wherein the database stores the encrypted data;

wherein the proxy devices each include an encrypted portion statistical data generation unit, which generates encrypted portion statistical data upon input of the proxy key generated by the proxy key generation unit with respect to the encrypted data stored in the database;

wherein the integrated data generation device includes an encrypted statistical data generation unit, which inputs the encrypted portion statistical data from each of the proxy devices and generates encrypted statistical data; and

wherein the integrated data storage device stores the encrypted statistical data.

2. The encrypted statistical processing system according to claim 1, wherein the proxy key generation unit generates a proxy key corresponding to the secret key of each of the service provider devices by allowing each of the service provider devices to input the secret key thereof and communicating with each of the service provider devices.

3. The encrypted statistical processing system according to claim 2, wherein the service provider devices each include a statistical information generation unit, which inputs the encrypted statistical data stored in the integrated data storage device and the secret key of each of the service provider devices and communicates with the other service provider devices to decrypt the encrypted statistical data and generate statistical information.

4. The encrypted statistical processing system according to claim 1, wherein, when the number of databases storing the encrypted data is 1 or greater integer N, a_i is the secret key of a service i, and y_i=ĝ

{a_i} is the public key in a situation where groups G and G_T have a prime order q, e( ) is a pairing function that is a map for group G_T when two members of G are input, g is a generator of group G, and q, e, g, and Z=e(g, g) are system parameters, the proxy key generation unit generates a proxy key including ĝ

{a_—

1a_—

2 . . . a_N/a_i} as a proxy key rk_i corresponding to the service i.

5. The encrypted statistical processing system according to claim 4, wherein the encrypted data generation unit generates encrypted data including (y_î

r, M·

Ẑ

r) as the encrypted data corresponding to the service i when a message is M and a random number of 1 or greater but smaller than q is r; and

wherein the encrypted statistical data generation unit generates encrypted statistical data including (e(gpk, g) ̂

R, S·

Ẑ

R) when the sum of random numbers used to generate encrypted data targeted for statistical information computation is R, gpk=ĝ

{a_—

1a_—

2 . . . a_N}, and the statistical information is S.

6. An encrypted statistical processing device comprising:

a key generation unit, which generates a service public key for encrypting data and a secret key corresponding to the service public key;

a proxy key generation unit, which generates a proxy key upon input of the service public key and the secret key;

an encrypted data generation unit, which generates encrypted data upon input of the service public key and predetermined data;

an encrypted portion statistical data generation unit, which generates encrypted portion statistical data with respect to the encrypted data upon input of the proxy key generated by the proxy key generation unit; and

an encrypted statistical data generation unit, which generates encrypted statistical data in accordance with the encrypted portion statistical data.

9. The encrypted statistical processing device according to claim 6, wherein, when the number of databases storing the encrypted data is 1 or greater integer N, a_i is the secret key of a service i, and y_i=ĝ

{a_i} is the public key in a situation where groups G and G_T have a prime order q, e( ) is a pairing function that is a map for group G_T when two members of G are input, g is a generator of group G, and q, e, g, and Z=e(g, g) are system parameters, the proxy key generation unit generates a proxy key including ĝ

{a_—

1a_—

2 . . . a_N/a_i} as a proxy key rk_i corresponding to the service i.

10. The encrypted statistical processing device according to claim 9, wherein the encrypted data generation unit generates encrypted data including (y_î

r, M·

Ẑ

r) as the encrypted data corresponding to the service i when a message is M and a random number of 1 or greater but smaller than q is r; and

wherein the encrypted statistical data generation unit generates encrypted statistical data including (e(gpk, g) ̂

R, S·

Ẑ

R) when the sum of random numbers used to generate encrypted data targeted for statistical information computation is R, gpk=ĝ

{a_—

1a_—

2 . . . a_N}, and the statistical information is S.

7. An encrypted statistical processing method comprising:

generating a service public key for encrypting data and a secret key corresponding to the service public key;

generating a proxy key upon input of the service public key and the secret key;

generating encrypted portion statistical data upon input of the proxy key with respect to encrypted data generated upon input of the service public key and predetermined data; and

generating encrypted statistical data in accordance with the encrypted portion statistical data.

8. (canceled)