In December 1954, the Communist Party divided the old UB into two parts: the Committee for Public Security (Komitet do spraw Bezpieczeństwa Publicznego, or KDSBP) and the Ministry of Internal Affairs (MSW).

The former was a secret police responsible for internal and external intelligence and counterintelligence to fight underground movements and the influence of the Catholic Church.

Recently released from prison, Władysław Gomułka became the first secretary of the Central Committee of the Polish United Workers' Party.

The introduction of Security Service to the Interior Ministry (which was already in the Polish public safety system since 1954), came as a result of directive number 00238/56 made by Władysław Wicha on 29 November 1956.

The tasks of the Security Service were identical to that of its predecessors (MBP, UB and KdsBP): to protect the communist system in the country (and beyond) through control and penetration into all structures of social life in Poland and abroad.

[4][5] The following ranks were observed until 1990:[6] After it was renamed the SB in 1956, it entered a period of relative inactivity during the era of reform instituted by Władysław Gomułka.

However, after 1968 it was revived as a stronger body responsible for political repression (most notably of the Solidarity movement, the leader of which, Lech Wałęsa, was under constant SB surveillance.