Under the Act on the Prevention of Divulgence and Protection of Industrial Technology, the government may review national security sensitive acquisitions concerning assets that hold "national core technology". 
On 21 February 2020, amendments to the Act came into effect, extending a prior notification requirement for foreign acquisitions of national core technology which hitherto only applied for companies that had developed this technology with government support to companies that have developed core technology without such help. The amendments also introduced a requirement that companies that hold national core technology that was developed with government support obtain prior government approval for any foreign capital contribution.
On 5 August 2020, amendments to the Enforcement Decree of the Foreign Investment Promotion Act entered into force. One of the changes has made it possible for the competent Minister or the heads of the relevant agencies to request a review to the Foreign Investment Committee on a foreign investment where there is a “high” possibility of leakage for core national technologies, as defined by the Act on the Prevention of Divulgence and Protection of Industrial Technology, and at the same time where a foreigner’s acquisition of de facto control over the management of an existing domestic company by acquiring its stocks, etc. may threaten national security.
"Article 2 (Definitions)  
The terms used in this Act shall be defined as follows: 
1. The term "industrial technology" means technology that falls under any of the following items which the heads of relevant central governmental administrative organs determine, publish, announce or authenticate in accordance with the order (limited to Presidential Decree, Ordinance of the Prime Minister and Ministerial ordinance; hereafter the same shall apply in this Article) delegated by an Act or the relevant Act to enhance the competitiveness of industries under their jurisdiction among the methods and technological information necessary for the development, production, dissemination and use of products or services:
(a) State-of-the-art technology under Article 5 of the Industrial Development Act;
(b) High technology under Article 18 (2) of the Restriction of Special Taxation Act;
(c) New technology under Article 15-2 of the Industrial Technology Innovation Promotion Act;
(d) New technology under Article 6-2 of the Electric Technology Management Act;
(e) Technology for components and materials under Article 19 of the Act on Special measures for the promotion of Specialized Enterprises, etc. for Components and Materials;
(f) New technology under Article 7 (1) of the Environmental Technology and Industry Support Act;
(g) Technology determined, published, announced or authenticated in accordance with the order delegated by other Act or the relevant Act.
2. The term "national core technology" means industrial technology designated under Article 9, which has high technological and economic values in the Korean and overseas markets or brings high growth potential to its related industries and is feared as a technology to exert an significantly adverse effect on the national security and the development of the national economy in the event that it is divulged abroad;
3. The term "national research and development project" means research and development projects advanced by the heads of relevant central governmental administrative agencies under Article 11 of the Framework Act on Science and Technology.
[...]
Article 11-2 (Overseas Acquisition, Merger, etc. of Institutions Possessing Industrial Technology which Possess National Core Technology)  
(1) Where an institution possessing industrial technology which holds national core technology developed with government subsidies for research and development intends to proceed foreign investment (hereinafter referred to as "overseas acquisition, merger, joint venture, etc.") of "overseas acquisition, merger, joint venture, etc." which is determined by Presidential Decree, it shall report in advance to the Minister of Knowledge Economy.
(2) Where an institution possessing industrial technology under paragraph (1) has noticed that overseas acquisition, merger, etc. is proceeding by foreigners determined by Presidential Decree, it shall immediately report such fact to the Minister of Knowledge Economy.
(3) Where the Minister of Knowledge Economy deems that the divulgence of national core technology under paragraphs (1) and (2) may seriously affect national security, he or she may, after consulting with the head of the relevant central governmental administrative agency, order institutions possessing industrial technology to take measures, such as suspension, prohibition, restoration to original state, etc. with respect to overseas acquisition, merger, etc. through the deliberation by the Committee.[...]" (Act on Prevention of Divulgence and Protection of Industrial Technology (No. 8062 of 2006), last amended by Act No. 17163 of 2020, Articles 2 and 11-2 [unofficial translation including amendments up to 2013-04-08])
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"Article 18-2 (Reporting, etc. of Overseas Merger and Acquisition, etc.) (1) “Foreign investment such as overseas merger and acquisition, joint venture, etc. which is determined by Presidential Decree” referred to in Article 11- 2 (1) of the Act means any of the following cases:
1. Where a foreigner, alone or with any of the following persons, holds 50/100 of the stocks or share (including a right to convert into stocks or share or to subscribe for stocks in the future; hereinafter referred to as "stocks, etc.") of an institution possessing industrial technology in possession of any national core technology (hereafter referred to an "institution in possession" in this Article) under Article 11-2 (1) of the Act (including cases of being in possession of less than 50/100 of stocks, etc., but, as a largest holder of stocks, etc., coming to be able to exercise controlling influence over either the appointment of executive officers or management of an institution in possession):
(a) The spouse, a blood relative within 8th degree of kinship, or a relative by marriage within 4th degree of kinship of the foreigner;
(b) A company in which the foreigner, either unilaterally or by a contract or agreement with a major stockholder or major right holder of share, can exercise controlling influence over major decision-making or business performance, such as organizational transformation or investment in new business;
(c) A company in which the foreigner, either unilaterally or by a contract or agreement with a major stockholder or major right holder of share, can appoint and dismiss its representative or appoint at least 50/100 of executive officers;
2. Where the foreigner intends to manage the institution in possession in a manner of taking over, taking on lease, or being entrusted with the management of, the whole or major part of the business of the institution in possession;
3. Where the foreigner becomes able to exercise controlling influence over the appointment of a majority or more of executive officers by renting or contributing fund to the institution in possession.
(2) “Foreigner determined by Presidential Decree” referred to in Article 11-2 (2) of the Act means any of the following persons:
1. An individual who has no nationality of the Republic of Korea;
2. A corporation established pursuant to the law of a foreign state;
3. An agency which vicariously conducts external economic cooperation affairs of a foreign government;
4. An international organization which deals with affairs concerning international finance, such as the International Bank for Reconstruction and Development, the International Finance Corporation, and the Asian Development Bank;
5. An international organization which deals with or vicariously conducts external investment affairs.[...]" (Enforcement Decree of the Act on Prevention of Divulgence and Protection of Industrial Technology (No. 20030 of 2007), last amended by No. 31380 of 2021, Article 18-2 [unofficial translation as of 24 October 2019])
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 "Article 4 (Liberalization, etc. of Foreign Investment)   
(1) Except as otherwise prescribed by the Acts of the Republic of Korea, a foreigner may engage in, without restraint, various activities of foreign investment in the Republic of Korea.
(2) No foreigner shall be restricted from making any foreign investment prescribed in this Act, except in the following circumstances:
1. Where he or she threatens national security and public order;
2. Where he or she has harmful effects on public health and sanitation or environmental preservation or is against Korean morals and customs;
3. Where he or she violates any Act or statutes of the Republic of Korea.
(3) The categories of businesses in which foreign investment is restricted in accordance with any of the subparagraphs of paragraph (2) and the details of restrictions shall be prescribed by Presidential Decree. [...]" (Foreign Investment Promotion Act (No. 5559 of 1998), last amended by Act No. 17799 of 2020, Article 4 [unofficial translation])
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" Article 5 (Types of Businesses Restricted on Foreign Investment, etc.) 
(1) The business types and restrictions on foreign investment in accordance with Article 4 ( 3 ) of the Act are as follows. [...]
2. Whether foreign investment that falls under any of the following items is a case that interferes with the maintenance of national security under Article 4 ( 2) 1 of the Act (hereinafter referred to as “national security risk”); Matters determined by the Minister of Trade, Industry and Energy to constitute a national security risk after deliberation by the Foreign Investment Committee at the request of the competent minister or the head of an intelligence investigation agency for review.
go. When a foreigner intends to acquire management control of an already established domestic company through acquisition of stocks, etc.
me. In case of any of the following
1) If there is a risk of impeding the production of defense industry materials (hereinafter referred to as “defense industry materials”) pursuant to Article 3, No. 7 of the Defense Business Act
2) In cases where there is a high possibility of being diverted for military purposes as goods or technologies subject to export permission or approval pursuant to Article 19 of the Foreign Trade Act
3) When there is a risk of disclosure of the contents of contracts, etc. treated as state secrets (hereinafter referred to as “state secrets” ) in accordance with Article 4, Paragraph 1, Item 2 of the National Intelligence Service Act
4) In case there is a risk of serious and serious hindrance to international efforts such as the United Nations for the maintenance of international peace and security
5) When there is a high probability of leakage of national core technology pursuant to Article 2, Item 2 of the Act on the Prevention and Protection of Disclosure of Industrial Technology [...]" (Enforcement Decree of the Foreign Investment Promotion Act (No. 15931 of 1998), last amended by No. 31811 of 2021, Article 5 [google translation])
Act on Prevention of Divulgence and Protection of Industrial Technology (No. 8062 of 2006), last amended by Act No. 17163 of 2020, Articles 2 and 11-2
Enforcement Decree of the Act on Prevention of Divulgence and Protection of Industrial Technology (No. 20030 of 2007), last amended by No. 31380 of 2021, Art 18-2
Foreign Investment Promotion Act (No. 5559 of 1998), last amended by Act No. 17799 of 2020, Article 4
Enforcement Decree of the Foreign Investment Promotion Act (No. 15931 of 1998), last amended by No. 31811 of 2021, Article 5
[<a href="https://www.law.go.kr/%EB%B2%95%EB%A0%B9/%EC%82%B0%EC%97%85%EA%B8%B0%EC%88%A0%EC%9D%98%EC%9C%A0%EC%B6%9C%EB%B0%A9%EC%A7%80%EB%B0%8F%EB%B3%B4%ED%98%B8%EC%97%90%EA%B4%80%ED%95%9C%EB%B2%95%EB%A5%A0">Act</a>],[<a href="https://elaw.klri.re.kr/eng_service/lawView.do?hseq=24351&lang=ENG">Act_Eng</a>],[<a href="https://www.law.go.kr/%EB%B2%95%EB%A0%B9/%EC%82%B0%EC%97%85%EA%B8%B0%EC%88%A0%EC%9D%98%20%EC%9C%A0%EC%B6%9C%EB%B0%A9%EC%A7%80%20%EB%B0%8F%20%EB%B3%B4%ED%98%B8%EC%97%90%20%EA%B4%80%ED%95%9C%20%EB%B2%95%EB%A5%A0%20%EC%8B%9C%ED%96%89%EB%A0%B9">Decree</a>],[<a href="https://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=DAF/INV/RD(2019)5&docLanguage=En">Decree_Eng</a>],[<a href="https://www.law.go.kr/LSW/lsInfoP.do?nwJoYnInfo=Y&ancNo=16131&chrClsCd=010202&efYd=20190401&lsiSeq=206503&efGubun=Y&ancYd=20181231#0000">Act</a>],[<a href="https://elaw.klri.re.kr/eng_service/lawView.do?hseq=44627&lang=ENG">Act_Eng</a>],[<a href="https://www.law.go.kr/%EB%B2%95%EB%A0%B9/%EC%99%B8%EA%B5%AD%EC%9D%B8%ED%88%AC%EC%9E%90%EC%B4%89%EC%A7%84%EB%B2%95%EC%8B%9C%ED%96%89%EB%A0%B9">Decree</a>]