Period between 1945 and 2002
The Section for Protection of People (OZN) was established on military principles on May 13, 1944 as central counter-intelligence and intelligence service within the Agency for People's Protection of the National Committee for Liberation of Yugoslavia. OZN operative unit was established on August 15, 1944 under the name of People's Defence Corps of Yugoslavia (KNOJ).
OZN field of activity included intelligence work directed abroad and towards occupied territory, counter-intelligence protection of liberated territory and military counter-intelligence work. OZN consisted of 6 divisions: first division – intelligence work, second division – counter-intelligence service in liberated territory, third division – counter-intelligence service in the army, fourth division – for statistics and technology, fifth division – for detecting and countering activities of foreign services (as of January 1945) and sixth division – for counter-intelligence protection of transportation objects and institutions in the country (as of April 1945).
The Section for Protection of People in Serbia was established in June 1944, while the same sections in Vojvodina and Kosovo and Metohia were set up in August the same year.
Furthermore, in October 1944 a special department of OZN was established for the City of Belgrade which was directly subordinate to the Ministry of National Defence of the Democratic Federative Yugoslavia.
After the adoption of Constitution of the Federal People's Republic of Yugoslavia (FNRY) on January 31, 1946, reorganisation of state bodies and state administration was performed according to which a part of OZN was transferred from the Ministry of National Defence to the Ministry of Interior.
At the end of the process in March 1946, I, II, V , VI and some parts of IV division (the Radio Centre and the Ciphering Group) of OZN were gathered to form the State Security Department (UDB).
UDB was strictly centralized and included: UDB in the Ministry of Interior (MUP) of FNRY, UDB bodies at the level of ministries and UDB authorizations for districts. As of July 1952, UDB members were introduced civil titles.
UDB had the following field of activity: "organising service, undertaking measures and performing governing tasks with the aim of detecting and preventing activities oriented towards undermining and disrupting constitutionally determined economic, political and legal order and gathering information to this effect."
UDB was divided into 8 departments: 1. Intelligence department, 2. Political department (struggle against internal enemy), 3. Counter-intelligence department, 4. Relations and keeping of records 5. Service for material and technical protection and financial affairs, 6. Counter-intelligence protection of the highest state and party officials, 7. Cryptography protection of secret data and 8. Personnel department.
After the Brijuni plenary session in July 1966, UDB was reorganised. The State Security Service (SDB) was established by the Basic Law on Internal Affairs within the Federal Secretariat for Internal Affairs (SSUP). State security work was decentralised, transferred to newly established republic and provincial security services within republic or provincial secretariats responsible for internal affairs, and directed, coordinated and harmonised by SSUP.
After the breakdown of SFRY, the State Security Directorate of the Republic of Serbia was established in the Republic of Serbia within the Ministry of Interior by the Law on Internal Affairs and the Decree on principles for internal organisation and systematization of working posts in ministries and specialised organizations from 1991.
The State Security Directorate ceased to exist in 2002 with the adoption of the Law on Security-Information Agency.
The Security-Information Agency is established in July 27, 2002 by the Law on Security-Information Agency. According to the law, for the first time in modern Serbian history civil security-intelligence work is separated from the Ministry of Interior.