The social life in every country is based on the sustained performance of their critical and sensitive infrastructures. It is for this very reason that hostile countries try to prevent this function from working in the target countries. Today, the development of information technology in cyberspace has caused some important parts of the way critical and sensitive infrastructures of the country function to come to rely on such space. Due to such dependence, the security of the infrastructures has been tied to the cyberspace. As far as the present research is concerned, it seeks to address the security defense indicators of the cyberspace of the critical and sensitive infrastructure across the country by considering the passive defense approaches, for in case the topic of this research is not attended to, the critical and sensitive infrastructure of the country will be highly likely exposed to cyber attacks. It should not be forgotten that according to ‘ Clausewitz’ , “ Every age has its own kind of war, its own limiting conditions” . By the same token, in the age of information, our country is in need of establishing the security-defense indicators of its own cyberspace that is replete with threats against which the resilience of the infrastructures can be enhanced by studying the present research. As such, these indicators have been constructed in three areas: human power, processes and technology using analytical-descriptive method via survey method and making maximum use of elites’ views. A statistical sample of 50 individuals has been selected for this research. The method of sampling was purposeful non-random sampling where the researcher has had direct reference to particular persons in a purposeful manner. The finding of the research indicates that each passive defense approach in the above-mentioned areas in relation with the security-defense indicators of the cyberspace of IRI’ s critical and sensitive infrastructures includes the following: human resources: “ instructing, informing and using local forces” with average agreement of 88%; processes: “ constructing the defense-security policy protocol, limiting the scope of performance, and mutual dependence” with average agreement of 45%; and technology: “ using intranet, localizing software and hardware, operating malware identification laboratories, encrypting data and using Firewall, and Honeypot and Intrusion Detection and Prevention System” , with average agreement of 98%.