CASE P-001Starter
Public Puzzle
Postcard From Nowhere
A quiet photograph, a station clock, and one place that fits every clue.
Review case Independent investigation platformFollow the evidence.
Follow the evidence.
Find the answer.
Logic puzzles for curious minds and hands-on security challenges for practitioners. Pick a case, inspect the clues, and prove what you found.
BASHCTF / ACTIVE CASEP-001
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Featured public puzzlePostcard
From Nowhere
Three details. One city. No specialist tools required.
Open case file
EVIDENCE 01
5Open cases
2Distinct tracks
0Unsafe targets
Choose your route
Two ways into the investigation.
Start where your curiosity is. Both tracks reward observation, reasoning, and a willingness to test an idea.
Selected case files
View all challenges Start with these.
CASE C-101Easy
Professional CTF
Header Trust
A development endpoint trusts a claim the browser is free to change.
Review caseThe ground rulesCuriosity works best
Curiosity works best
with clear boundaries.
Stay in scope
Only investigate the systems, files, and clues explicitly provided by a case.
Hints are part of learning
Use guidance when you need it. Getting unstuck is not the same as giving up.
Explain what you found
The strongest solve is one you can understand, repeat, and eventually teach.