All challenges
CH-05 Expert

The Vault Itself

No new vulnerability here. The grand-prize key was split into four fragments and scattered across the system you've already been breaking. Only a complete map of Season 1 reassembles it.

Objective

A recovered operations note describes the construction of the final key:

# Recovered note — vault operations Final Boss: The last key is split into 4 parts. Part 1 = chars 0-20 of stage 1 address Part 2 = chars 21-40 of stage 2 address Part 3 = chars 0-20 of stage 3 address Part 4 = last part hidden in /api/compute response Combine all 4, decode, profit.

Three fragments hide in plain sight — the stage wallets themselves. The fourth is only reachable through the RCE interface. Assembled in order, the fragments form a base58 secret key.

Key assembly

Paste each fragment as you recover it. Assembly and validation happen entirely in your browser — nothing is transmitted.

Fragment assembler base58 → ed25519 secret key
Fragment 1Stage 1 address · chars 0–20
Fragment 2Stage 2 address · chars 21–40
Fragment 3Stage 3 address · chars 0–20
Fragment 4Recovered via CH-04 · /api/compute

Hints

Hint 1 — The addresses are public
Fragments 1–3 come from the stage wallet addresses on the scoreboard — no exploitation required. Index carefully: character positions are zero-based, and the slices are exact.
Hint 2 — Fragment 4 requires CH-04
The final fragment only exists inside the server runtime. If you haven't solved Remote Code Execution, the compute endpoint is your way in. Enumerate the filesystem — the operations team left notes.
Hint 3 — Validate before you sweep
A valid Solana secret key is 64 bytes — 87–88 base58 characters. The assembler checks the decoded length. If it isn't 64 bytes, a fragment is wrong.

Claim the bounty

No submission form. No judging. The chain is the referee.

STEP 1

Reassemble

Combine all four fragments in order into the base58 secret key.

STEP 2

Import it

Load the key into any Solana wallet and confirm it controls the prize address.

STEP 3

Sweep the balance

Move the full 1 SOL to your own address. The season is yours.