SIGNAL RECEIVED — AWAITING AUTHORISATION
SUBSTATION ZERO
A cryptography-based investigation. Decode the signal chain. Find the source.
Learn real cryptography techniques while solving a Cold War intelligence investigation. Crack codes, intercept transmissions, and build genuine codebreaking skills through a story-driven puzzle adventure.
// WHO IS THIS FOR
// LIVE INTERCEPT — TRY IT NOW
An intercepted transmission has been recovered from Node Alpha. It appears to be encrypted. Can you decode it?
// INTERCEPTED FRAGMENT — NODE ALPHA
KHOOR DJHQW. WKLV LV QRGH DOSKD. SURFHHG WR VWDWLRQ-EUDYR.
Signal origin: unknown · Encryption: active · Status: awaiting decode
Move the slider to apply a Caesar shift and decode the message.
// WHAT TO EXPECT
Mission Briefing
// OPERATION NIGHTFALL — BRIEFING
Intel has intercepted a fragmented transmission from a dormant relay station. The signal cuts out before the message completes. Your objective: decode what was sent, trace each node in sequence, and report back before the window closes.
DIFFICULTY: RECRUIT · 5 NODES
Cipher Challenge
// NODE ALPHA — TRANSMISSION RECEIVED
KHOOR DJHQW. WKLV LV QRGH DOSKD. SURFHHG WR VWDWLRQ-EUDYR.
CIPHER TYPE: CAESAR · AWAITING DECODE
Leaderboard
// OPERATION NIGHTFALL — RANKINGS
// WHAT IS THIS
A chain of encrypted transmissions connects a series of relay nodes. Each node is locked behind a cipher. You will need to decode them, collect the fragments, and transmit your final report.
// WHAT YOU WILL NEED
Pattern recognition. Cipher knowledge. Source inspection. The ability to look beyond what is visible. Everything is documented in the Field Manual.
// SKILLS YOU'LL DEVELOP
Each mission teaches genuine cryptography techniques used by real intelligence services.
// MISSION INTELLIGENCE — DIFFICULTY OVERVIEW
| Operation | Classification | Nodes | Cipher Types |
|---|---|---|---|
| Operation Nightfall | Recruit | 5 | Caesar, Morse, Binary, Atbash, Source |
| Operation Blackout | Operative | 6 | Vigenère, Hex, Rail Fence, Steganography, Grid, ROT13 |
| Operation Cipher Six | Specialist | 7 | Affine, Book Cipher, Hex/Base64, File Metadata, Route Reconstruction, Contradiction, Pattern |
// MISSION ACCESS — WHAT YOU GET
Single Mission
£5.00
- Full mission with 5–7 cipher nodes
- Server-side timer and scoring
- Leaderboard placement
- Field Manual access
- Replay with alternate puzzle variants
All Three Missions
£12.00 Save £3
- Operations Nightfall, Blackout & Cipher Six
- 15+ cipher nodes across 3 operations
- Server-side timer and scoring
- Full leaderboard access
- Field Manual access
- Replay with alternate puzzle variants
No subscription. No time limit. Pay once, play at your own pace.