The Serviço de Informações de Segurança or SIS (Portuguese for: Security Information Service) is the Portuguese security agency and intelligence agency founded in 1984 that specialized in clandestine and covert operation, counterintelligence, counterterrorism, cybersecurity, HUMINT, intelligence assessment, and SIGINT. The function of SIS is to guarantee the internal security and prevent assassination of a high-ranking official, cyber attacks, espionage, insurgency, sabotage, terrorism, and the practice of acts which, by their nature, can change or destroy the Rule of Law as constitutionally established.