Which discipline focuses on protecting information that adversaries could exploit in daily operations?

• A. Information Security (INFOSEC)
• B. Emissions Security (EMSEC)
• C. Cyberspace Operations (CO)
• D. Operations Security (OPSEC)

Answer: (D)

The main idea is that Operations Security focuses on preventing adversaries from learning something sensitive from everyday actions and routines. OPSEC asks, what information could a daily operation reveal if it falls into the wrong hands, and how can we mask or protect that information in normal tasks, moves, communications, and procedures? It involves identifying critical information, spotting vulnerabilities in how we conduct regular activities, analyzing what threats could exploit those gaps, and implementing practical countermeasures—like altering procedures, limiting who knows certain details, or changing how we communicate about routines. This keeps routine operations from unintentionally revealing plans, capabilities, or intentions.

InfoSec, by contrast, is about protecting information and information systems overall through controls like access, encryption, and classification. EMSEC guards against unintended emissions that could leak information through devices or signals. Cyberspace Operations deals with actions in the cyber domain, including offensive and defensive cyber effects. So the discipline described is OPSEC because it targets how ordinary daily actions could expose information to an adversary and how to counter that risk.