Traffic Light Protocol (TLP): Securing Information Sharing

The Traffic Light Protocol (TLP) has been a well-known standard for controlling how sensitive information is shared. Whether sharing intelligence about cybersecurity threats, vulnerability disclosures, incident response coordination or law enforcement intelligence, TLP provides a simple framework for conveying sharing rules. Organizations across sectors rely on TLP to ensure critical information reaches those who need it while helping prevent unauthorized disclosure. While TLP is primarily used in professional security and intelligence contexts, it can be applied to almost any situation requiring controlled information sharing. The systematic approach to information distribution has practical value whenever controlling information flow is necessary.

In this article, we will be referring to the latest version of the TLP protocol, which is version 2.0, released on August 30, 2022. This update brings clarifications and enhancements to the framework ensuring it remains relevant in information sharing scenarios.

The application of TLP has transformed how sensitive information is handled across various sectors. While traditional classification systems are often complex and rigid, TLP offers a commonsense approach that can be implemented without extensive training or formal security clearances. Combined with its intuitive color-coding system and wide Threat Intelligence Platform adoption, this makes TLP a core component of modern information-sharing practices.

Before diving deeper into TLP specifically, it is important to understand the relationship between creating information and controlling its distribution. Creating valuable intelligence involves a 6-step process and requires considerable effort. However, even highly valuable intelligence can lose its effectiveness if not shared appropriately. Information and intelligence distribution controls like TLP recognize the value of intelligence depends not just on its content but on controlling who receives it and providing rules on how it can be shared. Without appropriate sharing restrictions, sensitive information may reach unintended audiences, potentially compromising sources, methods, investigations, or competitive advantages.

To properly implement TLP, it’s essential to understand how the framework defines different key groups:

• Organization: refers to the entity or group to which the recipient of TLP-marked information belongs. This could be a company, government agency, academic institution, or other group with clear boundaries and membership. When TLP guidance refers to sharing “within your organization,” it applies within this type of bounded entity.
• Clients: individuals or organizations with whom you have a direct service relationship and are authorized to receive services from your organization. These may include customers, constituents, or supported organizations who rely on your services or expertise. The distinction between organizational members and clients is particularly important for TLP:AMBER and TLP:AMBER+STRICT classifications.
• Community: refers to an industry group with a common mission or interest, such as the financial, healthcare, or cybersecurity professionals. For TLP:GREEN, understanding your community boundaries is crucial for appropriate information sharing.

The following image is directly sourced from the Forum of Incident Response and Security Teams (FIRST) website and  illustrates the official Traffic Light Protocol (TLP) levels and corresponding color codes. These standardized colors must be implemented precisely as to maintain consistency across security communications. The color palette has been optimized for accessibility, ensuring individuals with vision impairments can still effectively distinguish between classification levels when reading TLP-marked messages.

TLP provides a simple system for indicating how shared information can be distributed. While the protocol has evolved over time, understanding the core levels helps organizations implement appropriate controls.

TLP:RED – Highly Restricted – information represents the most sensitive category, restricted to specific participants only. This designation prohibits sharing beyond direct participants in a specific exchange or meeting.

TLP:AMBER+STRICT – Limited Sharing with No Redistribution – allows information to be shared only with members of your organization with a need to know, and specifically prohibits sharing with clients. Unlike TLP:AMBER, this designation removes the option for recipients to share with clients, creating a stricter boundary for sensitive information that must remain within an organization.

TLP:AMBER – Limited Sharing – information can be shared with members of an organization and their clients with a need to know. This level supports limited disclosure within communities and maintains privacy from public release.

TLP:GREEN – Community Sharing – information can be shared with peers and partner organizations within a sector or community but not publicly. This classification facilitates broader community awareness while preventing public distribution.

TLP:CLEAR – Unrestricted – (formerly TLP:WHITE) indicates information carrying minimal risk of misuse, allowing distribution without restriction, and subject to standard copyright rules. TLP:CLEAR is appropriate for information ready for public release or where broad distribution poses no risks.

One crucial aspect of TLP is recognizing that it’s not merely a labeling system and it is a practical tool requiring consistent implementation and respect. Organizations investing time in proper intelligence production must also invest in appropriate distribution controls. The ultimate measure of TLP’s effectiveness is not just the accuracy of its application, but the adherence to its restrictions by all recipients.

Despite its straightforward approach, applying TLP correctly can be confusing in complex real-world situations. For instance, determining exactly who constitutes your “organization” in a multinational corporation, or defining the boundaries of your “community” in overlapping industries can become challenging. Thankfully, the CISA TLP 2.0 User Guide provides excellent clarification through practical examples in Appendix C: TLP Use Cases. The appendix covers specific scenarios showing exactly how TLP should be interpreted in various contexts.

As you continue exploring OSINTNexus, you’ll find more detailed content about information sharing frameworks, including extended TLP implementations and alternative models. Whether you’re working in cybersecurity, threat intelligence, or sensitive business operations, understanding controlled information sharing practices will enhance your organization’s security posture and collaborative capabilities.

For deeper insights into TLP and information sharing controls, consider exploring these valuable resources:

FIRST TLP Definition and Usage

CISA Traffic Light Protocol 2.0 User Guide

CISA Information Sharing Guidance

National Council of ISACs