Research Library
Knowledge management
Explore methods and tools for connected notes and reusable research.
Keep ideas connected to their sources
Knowledge management is the practice of capturing, organizing, finding, and reusing what you learn. For a security discussion, that might mean keeping a question, the evidence behind it, and the links to related ideas together.
Zettelkasten: a method for connected notes
A Zettelkasten is a collection of individually addressable notes connected through references. Give an observation a focused note, explain it in your own words, retain its source, and link it to other notes with a reason for the connection. Index or overview notes provide useful starting points.
Niklas Luhmann’s note collection is a well-known historical example. The method can be practiced with paper or software. Apps provide places to store and connect notes; the working method comes from how you use them.
Explore the Niklas Luhmann Archive (German) (opens in a new tab) · Read a practitioner introduction to Zettelkasten (opens in a new tab)
A “second brain”: the broader idea
A second brain is a metaphor for an external system that helps you keep and reuse information beyond what you can remember unaided. It can include notes, documents, references, and work in progress. A Zettelkasten can be one part of that system.
Tiago Forte’s Building a Second Brain approach offers a particular workflow: Capture, Organize, Distill, and Express (CODE). CODE describes a workflow. You can choose tools and an organization pattern that fit your work.
Forte Labs: introductory guide to Building a Second Brain (opens in a new tab)
Tools to explore
Obsidian (opens in a new tab)
A note-taking application built around local Markdown files, links, backlinks, and a graph view. You can use it for connected notes or other ways of organizing your work.
TheBrain (opens in a new tab) / WebBrain (opens in a new tab)
TheBrain connects thoughts, notes, files, and links in a visual network. Its official WebBrain cloud-services page describes browser access, synchronization, and publishing or sharing a Brain.
When comparing tools, consider how you find an old idea, explain a connection, export your work, and keep backups. Before syncing or publishing, decide which notes should remain private and where copies will live.
Try a small experiment
- Read one useful article and write a short note about an idea in your own words. Keep the original link and date.
- Connect it to another note and explain why the relationship matters.
- Return later with a question. Can you find the note, check the source, and use it to explain something?
How do you keep your knowledge useful?
Do you use Zettelkasten, a second brain, Obsidian, TheBrain/WebBrain, or something else? Share whether and how it helps, what gets in the way, and how you keep your collection portable and private.
Discuss it in the SecSIG Forum (opens in a new tab) or email info@secsig.org.
Sources and links reviewed October 24, 2026. External publishers maintain their own material.