Operations security (OPSEC) is a process that identifies critical information to determine if friendly actions can be observed by enemy intelligence, determines if information obtained by adversaries could be interpreted to be useful to them, and then executes selected measures that eliminate or reduce adversary exploitation of friendly critical information. In a more general sense, OPSEC is the process of protecting individual pieces of data that could be grouped together to give the bigger picture (called aggregation). OPSEC is the protection of critical information deemed mission-essential from military commanders, senior leaders, management or other decision-making bodies. The process results in the development of countermeasures, which include technical and non-technical measures such as the use of email encryption software, taking precautions against eavesdropping, paying close attention to a picture you have taken (such as items in the background), or not talking openly on social media sites about information on the unit, activity or organization's Critical Information List. The term "operations security" was coined by the United States military during the Vietnam War. Process OPSEC is a five-step iterative process that assists an organization in identifying specific pieces of information requiring protection and employing measures to protect them: Identification of Critical information: Critical information is information about friendly intentions, capabilities and activities that allow an adversary to plan effectively to disrupt their operations. U.S. Army Regulation 530-1 has redefined Critical Information into four broad categories, using the acronym CALI – Capabilities, Activities, Limitations (including vulnerabilities), and Intentions. This step results in the creation of a Critical Information List (CIL). This allows the organization to focus resources on vital information, rather than attempting to protect all classified or sensitive unclassified information. Critical information may include, but is not limited to, military deployment schedules, internal organizational information, details of security measures, etc. Analysis of Threats: A Threat comes from an adversary – any individual or group that may attempt to disrupt or compromise a friendly activity. Threat is further divided into adversaries with intent and capability. The greater the combined intent and capability of the adversary, the greater the threat. This step uses multiple sources, such as intelligence activities, law enforcement, and open source information to identify likely adversaries to a planned operation and prioritize their degree of threat. Analysis of Vulnerabilities: Examining each aspect of the planned operation to identify OPSEC indicators that could reveal critical information and then comparing those indicators with