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  • What is Chaindeck?
    Chaindeck is a deck of square cards used for storing secret information. You arrange the cards in a specific way before writing the secret on the sides of the deck. Shuffling the cards will scramble the information, making it not possible to read. You can rearrange the cards any time to be able to read the secret again.
  • Why do I need Chaindeck?
    Chaindeck offers a unique solution to a common problem: how to securely store your seed phrase. While there are other options available, such as digital storage or physically written notes, these methods come with high risks and potential security vulnerabilities. They do not stop other people from being able to read your secret if they ever have possession. With Chaindeck, you have a non-digital encryption solution that offers a balance between convenience and security, so you can feel confident that your secret phrase is safe.
  • I already have my secret phrase written somewhere, can I transfer it to a new Chaindeck?
  • How do I write on the side of the deck?
    Place the arranged deck inside the sleeve box to make it easy to hold the deck together.
  • Are all decks the same?
    Each print/batch of Chaindeck has different random numbers on the cards. Chaindeck is printed in small batches.
  • Can I use more than one deck?
    Yes. There are many ways to combine multiple decks. Simplest way to combine them would be to stack them after arranging the cards on each deck separately.
  • How long can the Secret Phrase be?
    This depends on your handwriting and how much space you want to leave blank. The sides of the deck will have a total area close to a quarter of a standard letter size paper. However, remember that you will need to write legibly on uneven surfaces.
  • How big are the cards?
    Each card is 7 cm x 7 cm (2.75 inch x 2.75 inch). The 100 cards measure about 3.5 cm thick.
  • How are the cards made?
    Chaindeck cards are printed on professional standard card stock.
  • Are sides of the deck white? What color marker do I need?
    You will need a black or dark colored marker to record your seed phrase. Even though the face of the cards are black, the sides of the deck are white.
  • How long does it take to ship?
    Chaindeck orders ships within 1-3 business days.
  • Where do you ship?
    Currently we only ship to US. We are working to expand globally. Please contact us at if you don't want to wait, and we will try to arrange a custom order to your destination.
  • Do you accept returns?
    You can return unused items in accordance with our Return Policy within 15 days of order delivery. We also give refunds if the product has any defects, as outlined in our Return Policy.
  • What if I forget my PIN?
    There is no quick way to get your Secret Phrase if you don’t remember your PIN.
  • How do I find the Sorting Numbers?
    Use the 10x10 table printed on the cards. The first digit of your PIN is used for the rows, and the second digit is used for columns of the table. Each card will have a different Sorting Number for your PIN. Flip the card over (and keep it flipped) if there’s a dot where Sorting Number should be.
  • Why is the Sorting Number missing?
    Half the Sorting Numbers are on the other face of the card. Flip the card over, and keep it flipped. Finding the Sorting Numbers also is the step to flip the cards.
  • How do I find the Direction Arrows?
    Use the third digit of your PIN and the color of the Sorting Number to find the Direction Arrow. In the column corresponding to your PIN (on the 4x10 table of arrows), pick the arrow that is the same color as the Sorting Number for the card.
  • How long does it take to use Chaindeck?
    The cards must be arranged in a specific order ("chained") to create and retrieve the secret phrase. This depends on how quick you are with the cards. While an experienced owner can chain a deck of 100 cards in about 20 minutes, first-timers typically take about 45 minutes.
  • How can I make my Chaindeck more secure?
    After you've written your secret phrase and shuffled the cards, there will still be empty spaces available. Fill-in those empty spaces with random words and letters to "throw off" attackers. Shuffle again before storing. Furthermore, there are steps that can be taken to make it harder to decipher your deck, such as: - Customizing the PIN method - Writing the secret phrase small - Using multiple decks - Storing the deck separated in different locations - Writing decoy phrases after shuffling the cards to "throw off" others
  • How should I write my Secret Phrase?
    Try to write as small as possible while still being legible. Each continuous line across multiple cards can be used as a "hint" to decipher the deck.
  • What kind of pen should I use?
    We recommend you use a black medium tip permanent marker to write your Secret Phrase. You can also consider archival markers and pens.
  • Can my Chaindeck be deciphered?
    Any Chaindeck can be deciphered after enough time. There are steps that can be taken to make it harder to decipher, such as: - Customizing the PIN method - Writing the secret phrase small - Using multiple decks - Storing the deck separated in different locations - Writing decoy phrases after shuffling the cards to "throw off" others
  • Why paper?
    We tested plastic and metal cards, but paper turned out to be the best material for our purpose. There are several reasons for this. Plastic and/or metal cards do not absorb the ink, so they leak to other surfaces of the cards and make it easier to decode the deck. More importantly, it is much easier for the ink to rub-off when it is not absorbed into the material. We tested dozens of different markers (including laboratory-grade permanent markers, archival ink, and several others) on paper vs plastic/metal, and consistently found that ink on paper was the best at resisting mechanical and chemical damage.
  • What's the best way to store my Chaindeck?
    The biggest threats to losing written information are humidity and acidity. Air-tight containers make the deck much more vulnerable against these. A home safe that is fireproof and waterproof that stores Chaindeck can be a good way to protect against fire and flood. If you do this, please make sure you're thinking about moisture and acidity within the safe.
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