// Layers of Secrecy

Peel back two independently-encoded blocks from an intercepted transmission.

// Download

Intercepted Transmission Both encoded blocks, plus analyst notes

// Your Toolbox

CyberChef Drag-and-drop encode/decode recipes — From Base64, ROT13 Brute Force, Vigenère Decode.
base64 (CLI) `base64 -d` decodes a Base64 block from the command line.
Vigenère cipher A repeating-key substitution cipher — same key length as the alphabet shift pattern repeats.

// Situation

A two-block transmission was intercepted off an open relay. Each block was encoded independently, and neither uses an exotic format — just text transformations you can reverse by hand or with a tool.

// The Challenges

01 easy

Unwrap Block One

Block One has two layers: an outer wrapper you'll recognize instantly, and an inner substitution cipher that shifts every letter by the same fixed amount.

Target file: layers.txt (Block One)
02 medium

Break Block Two

Block Two resists a straight single-shift guess — it's a repeating-key cipher. The analyst notes hint at the keyword.

Target file: layers.txt (Block Two)