IT Security Outsourced IT

Traffic Light Protocol 2.0

What is TLP 2.0?

The Forum of Incident Response and Security Teams (FIRST) created the Traffic Light Protocol (TLP) standard which is used in the computer security incident response team (CSIRT) community to facilitate greater sharing of potentially sensitive information, more effective communication, and indicates any sharing limitations that recipients must consider when communicating potentially sensitive information with others1. In August 2020, FIRST published a new version of its TLP standard, TLP 2.0, which comes five years after its initial release.

Information sharing involves a source sharing information with a recipient. The source is responsible for ensuring that recipients of TLP-labeled information understand TLP standards and can follow TLP sharing guidance. The source may also impose additional sharing restrictions that recipients must follow. A recipient must obtain permission from the source before sharing information to a broader audience than what was indicated by the TLP label that came with the information.

TLP is a set of four labels considered valid by FIRST that indicate which sharing boundaries should be applied by recipients. In written form, the TLP labels must not contain spaces and should be capitalized. The four TLP labels are:

TLP:RED. For the eyes and ears of individual recipients only, no further disclosure. Sources may use TLP:RED when information cannot be effectively acted upon without significant risk for the privacy, reputation, or operations of the organizations involved. Recipients may therefore not share TLP:RED information with anyone else. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting.

TLP:AMBER. Limited disclosure, recipients can only spread this on a need-to-know basis within their organization and its clients. TLP:AMBER+STRICT restricts sharing to the organization only. Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risk to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may share TLP:AMBER information with members of their own organization and its clients, but only on a need-to-know basis to protect their organization and its clients and prevent further harm. Note: if the source wants to restrict sharing to the organization only, they must specify TLP:AMBER+STRICT.

TLP:GREEN. Limited disclosure, recipients can spread this within their community. Sources may use TLP:GREEN when information is useful to increase awareness within their wider community. Recipients may share TLP:GREEN information with peers and partner organizations within their community, but not via publicly accessible channels. TLP:GREEN information may not be shared outside of the community. Note: when “community” is not defined, assume the cybersecurity/defense community.

TLP:CLEAR. Recipients can spread this to the world, there is no limit on disclosure. Sources may use TLP:CLEAR when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:CLEAR information may be shared without restriction.

1 FIRST, 2022, “Traffic Light Protocol (TLP): FIRST Standards Definitions and Usage Guidance – Version 2.0”