Halloween at the Portal. The Hollow, a haunted cipher maze, is free to play until 2 November. Enter The Hollow

๐Ÿงญ This chain is also a 3D maze

The Ledger is this same chain as a place you walk through. Each stage is a terminal beside a locked gate, and solving it opens the gate. The maze also hides data fragments with a bonus message you can only get there.

Your progress and score are the same either way, so you can start in one and finish in the other. If you want the maze to be a surprise, start there.

๐Ÿ”’ See the maze (Elite) Solve it here as a page โ†“

๐Ÿ“œ Briefing
This maze is not built from walls. It is built from blocks, each one sealed with the fingerprint of the one before, so that nothing written here can be quietly changed. Somebody changed something anyway.

Four gates stand along the chain. The terminals do not ask you to decipher anything. They ask you to do what a node does: hash, check, combine and mine. The workbench holds the tools: SHA-256 Hash, Merkle Root and Proof of Work. Hashes are unforgiving: one wrong letter, one extra space or the wrong case gives a completely different result.
  1. 1 Gate One - The Fingerprint
  2. 2 Gate Two - The Broken Link ๐Ÿ”’ opens with stage 1's answer
  3. 3 Gate Three - The Root ๐Ÿ”’ opens with stage 2's answer
  4. 4 Gate Four - The Seal ๐Ÿ”’ opens with stage 3's answer

Log in to play

Scored puzzles need a free account: your time and hints are tracked by the server, points go on the leaderboard, and each answer unlocks the next stage.

Create a free account Log in

New here? The five tutorials need no account.