Skip to menu Skip to content

Korean e-government homepage mark This site is the official e-Government website of the Republic of Korea.


PseudonymizationㆍCombination of Pseudonymized Information


What is pseudonymized information?

Information that makes it impossible to identify a particular individual without the use or combination of additional information for restoring the information to its original state by pseudonymizing personal information

Legal basis

  • Paragraph 2 of Article 28-1 of the Personal Information Protection Act (Definitions)
  • Paragraph 2 of Article 28-2 of the Personal Information Protection Act (Processing of Pseudonymous Data)

Necessity of pseudonymization

As personal information contains any information about an individual, various problems may occur, such as violation of privacy in the process of processing/using the personal information. To safely use personal information, technical safety measures (pseudonymization) are taken to prevent information about a particular individual from being exposed.

Purposes and targets of pseudonymization

  • Statistics
    Quantitative information about a particular group or target
  • Scientific research
    Research that applies scientific methods, e.g. development and demonstration of technologies, fundamental research, applied research and privately-funded research
  • Archive in the public interest
    Preserving records and information that need to be continuously accessed for public interests

Pseudonymization Process

See below See below
    1. STEP 1
    2. Preparation
    3. (Suitability for purpose and preliminary plan)
    1. STEP 2
    2. Pseudonymization
    3. (Defining the level of pseudonymizing information and processing)
    1. STEP 3
    2. Adequacy Review & Additional Processing
    3. Preserving records worth accessing continuously for the benefit of the public
    4. Adeguate
    5. Follow-up
    6. Inadeguate
    7. (Defining the level of pseudonymizing information and processing)

1. Preparation

Set up a preliminary plan including specific purposes to define the subjects and the level of pseudonymization.

2. Pseudonymization

In the process of pseudonymization, too, the principle of minimum use and collection of personal information should be maintained. In order to decide the method of pseudonymization, processing (provision) environment, purpose of processing, type of information, and others shall be considered comprehensively.

3. Adequacy Review & Additional Processing

Final evaluation as to whether pseudonymization was performed on a proper level to fulfill the purpose, and whether there is any risk of re-identification.

4. Follow-up management

Technical, managerial, and physical measures including compliance with laws must be taken for the pseudonymized information which has been evaluated as adequate.

Combination Procedure

Combining pseudonymized information

According to Article 28-3 of the Personal Information Protection Act, the combination of pseudonymized information processed by different personal information controllers for statistical purposes, scientific research and preservation of records for public interests shall be conducted by a specialized institution designated by the Protection Commission or the head of the related central administrative agency.

Legal basis

  • Article 28-3 of the Personal Information Protection Act (Restriction on Combination of Pseudonymous Data)
  • Article 29-2 of the Enforcement Decree of the Personal Information Protection Act (Combination of Pseudonymous Data among Personal Information Controllers)
  • Notification on the combination and export of pseudonymized information

Combination procedure

See below Enlarge image
  1. Requesting Organization A
  2. Attributer
  3. Concatenated Key
  4. Serial No. A
  5. Requesting Organization B
  6. Serial No. B
  7. Attributer
  8. Concatenated key
  9. Transfer the concatenated key created through a method agreed upon by the management agency
  10. Concatenated Key Management Agency
  11. Transfer the linker information for the key
  12. Special Organization for Combination
  13. Combination
    1. (If requested)
    2. Review for Release
    3. Release if the result is satisfied
    4. Release