Military Security is the principal and most effective intelligence service in the country. Its chief in 1993, General Mohamed Médiène, was believed to number among the more influential officers of the ANP. After Boumediene took power in 1965, he relied on Military Security to strengthen his control over the ANP during the difficult process of amalgamating "external" and "internal" ALN personnel, some of whom were of questionable loyalty. Military Security became the dominant security service in the 1970s, responsible to the head of state for monitoring and maintaining files on all potential sources of opposition to the national leadership.

Although theoretically bound by the same legal restrictions as the Sûreté and gendarmerie, Military Security is less circumscribed in its operations. Frequent cases of incommunicado detention of suspects have been ascribed mainly to Military Security. An important role in the area of national security was later assumed by the General Delegation for Documentation and Security (Delégation Générale de Documentation et Sûreté--DGDS) as the principal civilian apparatus for conducting foreign intelligence and countering internal subversion. The security services are believed to infiltrate Islamist groups, to employ paid informers for monitoring opposition movements, and to practice extensive telephone surveillance without prior court authorization as required by law. During and after the riots of October 1988, widely published accounts told of torture and other human rights abuses of detainees. Both Military Security and the DGDS were implicated in the brutal treatment of detainees to obtain confessions or extract information on clandestine political activists. Government officials have acknowledged that individual cases of improper behavior by security forces occurred but stressed that torture was not sanctioned and that evidence of it would be investigated.

In September 1990, Benjedid announced the dissolution of the DGDS after criticism of its repressive role in the 1988 riots. The dissolution coincided with other government reforms to remove barriers to individual liberties. Informed sources believed, however, that this action did not represent an end to domestic intelligence operations but rather a transfer of DGDS functions to other security bodies. Surveying the intelligence picture in August 1992, the French periodical Jeune Afrique concluded that Military Security, with its abundant documentation on the leadership and organization of the violent Islamist groups, remained the senior intelligence body concerned with internal security. Other intelligence groups include a Coordinating Directorate of Territorial Security, an Antiterrorist Detachment, and a working group of the High Council of State charged with political and security matters. The precise functions and jurisdictions of these bodies remain fluid, according to Jeune Afrique.

Data as of December 1993