The Traffic Light Protocol (TLP) has been included in CompTIA cyber security exam objectives (Security+, CySA+, and CASP+, now known as SecurityX), going back several revisions. TLP is a set of rules that pertain to information sharing and disclosure. In this case, the simple concept of roadway traffic lights is applied to information sharing. The TLP is a tool for ensuring sensitive information reaches the right people. FIRST, an organization formed by cyber first responders, defines it. It consists of designations used to share information with the appropriate audience.

According to the TLP, when sharing information between two parties (source and recipient), the traffic light colors have a specific function. They instruct the party receiving the information (the recipient) on the expectations of the party sending the information, which pertain to how the information will be used.

The key to understanding TLP is its simplicity. Traffic lights or signals are used and seen by drivers and passengers on roadways worldwide.

Everyone in an organization handling information must understand and use TLP in the same way. The successful implementation of TLP in an organization is achieved when everyone uses the protocol to process information similarly.
While most roadway traffic signals have two or three lights, the protocol defines four conditions.

TLP: Red – information classified as RED when the party sharing the information intends that it will not be disclosed. The use of this information should be restricted to participants only. I tell people that when information classified as TLP: Red is shared with you, that information should stay with you.

TLP: Amber – information classified as AMBER is intended for limited disclosure. That means you should only share this information with people in your organization. If you work for a company in the Information Security department, you can share information classified as TLP: Amber with others in your department. Some organizations stretch this to be interpreted as within the company. Specific company policies and procedures should clarify this.

TLP: Green—Information classified as GREEN also limits disclosure; however, disclosure should be limited to the community: people in your organization and other organizations you regularly work with. Like TLP: Amber, your organization’s policies and procedures should define the community.

TLP: White – information classified as TLP: White “carries minimal or no foreseeable risk of misuse” and can be shared broadly. It’s important to note that information classified as TLP: White is still subject to other organizational information classifications. These may include Secret, Top Secret, or NoForn. Additionally, copyrights should be observed.

NOFORN, short for “Not Releasable to Foreign Nationals,” is a security marking used on U.S. government information. It restricts disseminating the marked information to anyone who is not a U.S. citizen or has the appropriate security clearance. This means that foreign nationals, dual citizens, and even some U.S. citizens representing foreign interests are prohibited from accessing or receiving the information.

The TLP is an important cybersecurity threat intelligence designation. It is one of the many topics on the CompTIA Security+ SY0-701 exam.