Operations Security (OPSEC) is a process that identifies non-illicit means that a potential attacker can use to reveal critical or sensitive information and data. OPSEC uses countermeasures to reduce or eliminate an attacker’s exploitation of such information to prevent this action by a potential attacker. Just like OSINT, OPSEC can trace its origins to U.S defense and military interests. The term OPSEC was originally created during the Vietnam War campaign by the U.S military when unclassified information was inadvertently found to be shared with the North Vietnamese and their allies.
The relationship between OSINT and OPSEC lies in how one balances the other. OSINT is the practice of collecting information from published or publicly available sources for intelligence purposes. OPSEC concerns the protection of individual pieces of data that can be aggregated to form a bigger, potentially critical/sensitive picture. Without OPSEC, there is a chance for OSINT tools and techniques to be used by potential attackers for illicit reasons. Therefore, to protect the legality of using OSINT tools and techniques, OPSEC is a necessary enforcer.