Frequently Asked Questions

BIP39 (Bitcoin Improvement Proposal 39) is an open Bitcoin standard that defines how a wallet seed is represented as a human-readable mnemonic phrase. The standard specifies a fixed list of exactly 2,048 English words; each word is uniquely identified by its first four letters, which makes the list resistant to typos and ambiguity.

When you create a new Bitcoin wallet — or most other cryptocurrency wallets — your recovery phrase is drawn from this fixed list of 2,048 words. Every BIP39-compatible wallet can restore a seed from the same mnemonic, which is why the standard has become the de-facto interoperability format across Ledger, Trezor, BitBox, Sparrow, Electrum, and virtually all modern wallets.

Because the list is fixed and public, knowing which words it contains — and where they appear in a specific book — makes it possible to encode your entire seed phrase as a short set of position numbers.

A Book Cipher is a centuries-old encryption technique that uses a specific book as the shared key between sender and receiver. Instead of storing a secret directly, you record the position of each word within the book — for example, page 42, line 7, word 3.

Anyone without the exact book sees only a list of meaningless numbers. BIP39 Books adapt this method for modern Bitcoin seed backup.

The protection comes from separating the information into two independent pieces. The book alone is just a story — it reveals nothing about your seed. The encoded numbers alone are meaningless without the book.

Only someone who has both pieces — and knows how you applied the cipher — can reconstruct your seed phrase. By storing them separately, you eliminate any single point of failure.

Veit the Fox is a 104-page book aimed at Bitcoiners with kids. You can read it to your kids while it quietly serves as your seed backup reference.

777 Wisdoms for Every Day is a collection of daily wisdom quotes suited for any adult bookshelf, nightstand, or travel bag. Both books contain all 2,048 BIP39 words and work identically as cipher tools.

If you have children: choose Veit the Fox. It doubles as a genuine read-aloud book and a seed backup reference.

If you do not have children or prefer something for daily use: choose 777 Wisdoms for Every Day. Both books work equally well as Book Cipher tools — the choice is purely about which fits your shelf and lifestyle.

No — both books are published in English only, because the BIP39 standard itself is built around an English word list.

The Book Cipher method requires the book to contain exactly the 2,048 words of the BIP39 English word list. This is the list that virtually every Bitcoin wallet generates and expects by default — Ledger, Trezor, BitBox, Sparrow, Electrum, and most others. BIP39 defines additional word lists in a handful of other languages (Spanish, French, Italian, Japanese, Korean, and a few more), but those are rarely enabled in practice and contain an entirely different set of 2,048 words. So building the book around any language other than English would only work for a small fraction of wallets.

Weaving all 2,048 words unobtrusively into a natural story or a wisdom collection is only feasible with the English list. A German, Spanish, or French "translation" wouldn't really be a translation — it would have to be a completely different book built around a different word list, and it would only work for users whose wallet was explicitly configured for that language.

The good news: you don't need to actually read the book to use it as a cipher tool. You only need to locate specific English words at specific page-line-word positions — that works regardless of your English reading level. For readers who also want to enjoy the text: 777 Wisdoms consists of short, standalone aphorisms accessible with basic school English, and Veit the Fox doubles as an English bedtime read for the family.

Yes. Every single one of the 2,048 BIP39 seed words appears in each book, in its exact dictionary form. The words are woven naturally into the text so that the book reads authentically.

A downloadable word index is available for each book to help you locate any word quickly.

Yes — you can encode your seed phrase with either book, or even with both for redundancy. However, the encoded numbers are specific to each book. A reference like 47-3-5 points to a different word in Veit the Fox than in 777 Wisdoms.

This means: numbers created with one book cannot be decoded with the other. Always use the same book for encoding and decoding.

No. The BIP39 words appear naturally within the text without any highlighting, bold formatting, or special markers. The books read like ordinary stories or quote collections.

A separate downloadable word index PDF shows you the exact page location of every BIP39 word.

The Book Cipher is only as secure as your operational security. The book alone reveals nothing about your seed. The encoded numbers alone reveal nothing. Only someone who has both pieces — plus knowledge of your encoding format — can decode your seed phrase.

Keep the book and the numbers in separate, secure locations and you control the security entirely.

It looks like a normal book. There are no references to Bitcoin, seed phrases, or cryptocurrency anywhere inside. Words like "seed" or "satoshi" may appear because they are part of the BIP39 word list, but they are used naturally in context.

A person who finds the book has no reason to suspect it has any connection to a digital asset backup.

No. No single backup method should ever be your only backup. Use a BIP39 Book as one layer in a broader backup strategy alongside other methods such as metal plates or other secure storage.

Multiple independent backups stored in multiple locations is the gold standard for seed phrase security.

Yes, and this is an excellent combination. Engrave the encoded numbers (not the seed words themselves) onto a metal plate for fire and flood resistance. A set of numbers engraved on metal is far less recognizable as a Bitcoin backup than 24 English seed words.

The book provides the decoding key; the metal plate stores the encoded reference durably. The two methods complement each other well.

Get the book, then use the word index to find the page location of each word in your seed phrase. Note the position (page, line, word number) for each seed word. Store this list of numbers separately from the book.

To recover your seed, look up each position in the same edition of the book. See the How It Works page for a full step-by-step guide.

Both books are available on Amazon worldwide. Veit the Fox is also stocked by major European bookstores including Thalia, Bücher.de, Hugendubel, and Osiander.

See the individual book pages for direct purchase links: Veit the Fox | 777 Wisdoms. Or start from the bitcoin seed book overview on our homepage.

Yes. Always use the same print edition consistently. Page numbers can differ between editions, which would make your encoded references unreadable with a different print.

We recommend keeping a backup copy of the exact same print to ensure long-term consistency.

No, and this is deliberate. A seed backup tool should never exist in digital form. An eBook can be copied, intercepted, indexed, or lost when a device fails.

The physical printed book is part of the security model — it has no digital attack surface.

The most common format is page-line-word (e.g., 42-7-3 means page 42, line 7, word 3). You can also use page-word if you prefer a shorter notation. For 777 Wisdoms for Every Day, you can use wisdom-number-line-word or wisdom-number-word format.

You can also disguise the numbers further — formatted as phone numbers, GPS coordinates, or any other innocuous-looking sequence — as long as you remember your own encoding scheme and document it securely.