Common data determining methods, apparatuses, and systems for protecting privacy

Patent metadata

Field	Value
Publication number	US-12400027-B2
Application number	US-202318315197-A
Country	US
Kind code	B2
Filing date	May 10, 2023
Priority date	May 10, 2022
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

Methods, apparatuses, and systems for protecting privacy are described. In an example, a first party encrypts a first data set, and sends a single-encrypted full data set to a second party. The second party re-encrypts the single-encrypted full data set to obtain a double-encrypted full data set, obtains a single-encrypted sampling data set, and sends the single-encrypted sampling data set to the first party. The first party encrypts the single-encrypted sampling data set to obtain a double-encrypted sampling data set, determines an intersection of the double-encrypted full data set and the double-encrypted sampling data set, performs upsampling on a complement other than the intersection in the double-encrypted sampling data set to obtain a noise-added intersection, and sends an element index of the noise-added intersection to the second party. The second party determines related information of common data based on the element index.

First claim

What is claimed is:

1. A computer-implemented method for protecting privacy, performed by a first party, and comprising:
encrypting, by using a first key held by the first party, each piece of first data in a first data set held by the first party, to obtain a first single-encrypted full data set;
sending the first single-encrypted full data set to a second party;
receiving a first double-encrypted full data set and a second single-encrypted sampling data set from the second party, wherein the first double-encrypted full data set is obtained by at least re-encrypting each piece of data in the first single-encrypted full data set by using a second key of the second party, and the second single-encrypted sampling data set is obtained by performing first sampling and single-encryption based on the second key on a second data set held by the second party;
re-encrypting the second single-encrypted sampling data set by using the first key to obtain a second double-encrypted sampling data set;
determining an intersection of the first double-encrypted full data set and the second double-encrypted sampling data set as an original intersection;
performing second sampling on a complement other than the original intersection in the second double-encrypted sampling data set to obtain one or more obtained additional elements;
adding the one or more obtained additional elements to the original intersection to obtain a noise-added intersection; and
sending an element index of the noise-added intersection to the second party.

2. The computer-implemented method according to claim 1 , wherein the first data set comprises a user account or user personal information as the first data.

3. The computer-implemented method according to claim 1 , wherein the encrypting, by using a first key held by the first party, each piece of first data in a first data set held by the first party comprises:
calculating each hash value corresponding to the each piece of first data by using a hash function; and
respectively performing an encryption operation on the each hash value by using the first key to obtain the first single-encrypted full data set.

4. The computer-implemented method according to claim 1 , wherein the second sampling comprises:
performing sampling on one or more elements in the complement based on a second probability, wherein the second probability is negatively correlated with a predetermined second privacy budget.

5. The computer-implemented method according to claim 1 , wherein the first double-encrypted full data set is obtained by disordering and re-encrypting based on the first single-encrypted full data set.

6. A computer-implemented method for protecting privacy, performed by a second party, and comprising:
receiving a first single-encrypted full data set from a first party, wherein the first single-encrypted full data set is obtained by encrypting, by using a first key, each piece of first data in a first data set;
at least re-encrypting each piece of data in the first single-encrypted full data set by using a second key of the second party to obtain a first double-encrypted full data set;
performing first sampling and single-encryption based on the second key based on a second data set held by the second party to obtain a second single-encrypted sampling data set;
sending the first double-encrypted full data set and the second single-encrypted sampling data set to the first party;
receiving an element index of a noise-added intersection from the first party, wherein:
the noise-added intersection is obtained by adding one or more additional elements to an original intersection,
the original intersection is an intersection of the first double-encrypted full data set and a second double-encrypted sampling data set,
the second double-encrypted sampling data set is obtained by encrypting the second single-encrypted sampling data set by using the first key, and
the one or more additional elements are obtained by performing second sampling on a complement other than the original intersection in the second double-encrypted sampling data set; and

determining related information of common data based on the element index.

7. The computer-implemented method according to claim 6 , wherein the second data set comprises a user account or user personal information.

8. The computer-implemented method according to claim 6 , wherein the first double-encrypted full data set is obtained by operations comprising:
disordering each piece of data in the first single-encrypted full data set, and re-encrypting each piece of disordered data by using the second key; or
re-encrypting each piece of data in the first single-encrypted full data set by using the second key, and disordering re-encrypted data.

9. The computer-implemented method according to claim 6 , wherein the second single-encrypted sampling data set is obtained by operations comprising:
performing first sampling on the second data set held by the second party, and applying single-encryption based on the second key to a sampling data set obtained through first sampling; or
applying single-encryption based on the second key to each piece of second data in the second data set held by the second party, and performing first sampling on a second single-encrypted data set obtained through single-encryption.

10. The computer-implemented method according to claim 6 , wherein the single-encryption based on the second key comprises:
calculating each hash value of each encryption object by using a hash function; and
respectively performing an encryption operation on the each hash value by using the second key.

11. The computer-implemented method according to claim 6 , wherein the first sampling comprises:
for each element in a target set to be sampled, reserving the element as a sampling element based on a first probability, wherein the first probability is positively correlated with a predetermined first privacy budget.

12. The computer-implemented method according to claim 6 , wherein the determining related information of common data based on the element index comprises:
determining corresponding second data in the second data set as noise-added common data based on the element index.

13. The computer-implemented method according to claim 12 , wherein the determining related information of common data based on the element index further comprises:
obtaining an attribute feature of each object corresponding to the noise-added common data; and
determining, based on the attribute feature of each object, a noise-added statistical result of the common data related to the attribute feature.

14. The computer-implemented method according to claim 13 , wherein the noise-added statistical result comprises one of an average, a distribution, a total, or a mean square error.

15. A computer-implemented method for protecting privacy, comprising:
encrypting, by a first party by using a first key, each piece of first data in a first data set held by the first party to obtain a first single-encrypted full data set;
sending, by the first party, the first single-encrypted full data set to a second party;
at least re-encrypting, by the second party, each piece of data in the first single-encrypted full data set by using a second key to obtain a first double-encrypted full data set;
performing, by the second party, first sampling and single-encryption based on the second key based on a second data set held by the second party to obtain a second single-encrypted sampling data set;
sending, by the second party, the first double-encrypted full data set and the second single-e

Assignees

• Alipay Hangzhou Inf Tech Co Ltd

Inventors

• Du Jian
• Cui Jinming
• Zhang Lei
• Lu Yufei
• Duan Pu

Classifications

• G06F21/64

  Protecting data integrity, e.g. using checksums, certificates or signatures · CPC title

• G06F21/602 Primary

  Providing cryptographic facilities or services · CPC title

• G06F21/6245 Primary

  Protecting personal data, e.g. for financial or medical purposes · CPC title

• G06Q40/03

  Credit; Loans; Processing thereof · CPC title

• G06Q30/0277

  Online advertisement · CPC title