What is Chaindeck? A detailed product description.

Chaindeck is a physical cryptographic system. It is a deck cipher made of 100 durable square cards. Each card’s edges align to let you record a secret phrase along the four sides of the deck, then conceal it by changing the deck’s arrangement (i.e. shuffling the cards). The product includes everything needed to set up the deck and preserve the phrase for long-term, offline storage.

Chaindeck Original comes with a deck of100 square cards, a deck sleeve (not shown), and instructions booklet in a protective deck box.

How it works

1. Arrange — You establish an arrangement for the cards. Many owners choose a simple 3-digit PIN–based method that maps directly to a repeatable chain (order+rotation+flip). Others invent custom, PIN-less arrangements, leveraging the huge space of possible sequences.

2. Record — You write the secret phrase on the sides of the deck. The ink penetrates the cardstock, making markings permanent and resistant to fading or smudging.

3. Conceal — Shuffle the cards. As the arrangement changes, the phrase is no longer readable at a glance. Re-create to the original arrangement of the cards to reveal it.

   
   

Delayed-access security

• PIN = Fast path. With the correct PIN method, you can re-create the arrangement of the cards and read the phrase. It usually takes 15 to 30 minutes to arrange all 100 cards.

• No PIN = Very slow path. Without the PIN, access may still be possible but very slow. An attacker must either:

  • Try most PINs (time-consuming), or

  • Reconstruct the original order like a jigsaw puzzle, which can be painstaking especially if you’ve added decoys.

• False markings (decoys). Owners can add false or misleading edge markings so that puzzle-style reconstruction becomes significantly harder and slower for anyone without the intended method.

  
  

Combinatorial hardness

Each card can be reordered, flipped, and rotated, creating an astronomical number of possible deck states.

• Owners can design unique, PIN-less ordering schemes that exploit this vast state space, adding security through obscurity of method and sheer combinatorial complexity.

  
  

Advanced usage

• Multiple decks. Owners can combine or segment secrets across multiple Chaindecks (e.g., split phrases, split decks, or multi-part recovery plans) to add redundancy or threshold-style recovery.

• Inheritance & beyond. Chaindeck supports inheritance planning (e.g., sealed instructions with a recovery path), disaster recovery kits, shared custody arrangements, and other workflows where possession should not equal immediate access.

  
  

Why Chaindeck

• Offline & durable. No electronics, batteries, or apps required; resistant to smudging and built for long-term storage.

• Tamper-evident by design. Unauthorized attempts to reconstruct or test PINs often leave telltale handling patterns.

• Separation of possession and access. Even if someone obtains the deck, reading the phrase requires time and intentional effort—fast with your method, slow and laborious without it.