Amulet ₿

Offline Bitcoin Wallet Generator — single HTML file, zero dependencies, fully verifiable.

Amulet generates BIP-39 seed phrases with high, auditable entropy and derives all standard wallet formats directly in your browser. Nothing is transmitted — ever. Close the tab, and the keys exist only where you wrote them down.

Check the file hash:

SHA256 : D3BB5AE1A50501C7E8E4EDF03B2068C90105370207E3AB39F8D43D6AE82DB22D MD5 : 20D56BA1F7A8934B27491EEF3214D556

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Why Amulet?

Most wallet generators ask you to trust their randomness. Amulet lets you verify it. Every seed report includes the exact combined input string, intermediate SHA-256 hashes, checksum bits, and step-by-step instructions to reproduce the mnemonic offline with nothing but a SHA-256 tool and the BIP-39 wordlist.

It ships as a single .html file — no build step, no server, no installs, no apps to trust, and no frameworks. Download the file, save it locally, disconnect from the internet, and open it in any modern browser.

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Features

Entropy & Seed Generation

• 12-word or 24-word BIP-39 mnemonic (128-bit or 256-bit entropy)
• CSPRNG base layer — crypto.getRandomValues() provides 256 bits by default
• Five entropy sources that mix into the seed via SHA-256(csprng ‖ user_input):
  • CSPRNG only — browser's cryptographic RNG (sufficient on its own)
  • Dice rolls — D6 values, with a bit counter (50 rolls ≈ 128 bits, 99 ≈ 256 bits)
  • Playing cards — full 52-card deck, 4-card draws across multiple rounds with duplicate detection
  • Random keystrokes — live Shannon, bigram, Rényi-2, LZ78, and $\chi^2$ entropy analysis with keyboard-walk detection
  • Chaos Grid — a 5×5 interactive tile-flip game that records timestamps and pointer coordinates as entropy
• Automatic checksum — SHA-256 of the entropy determines the final BIP-39 checksum word
• Entropy quality scorecard — rates your combined entropy and flags weak patterns

Address Derivation

• Legacy — BIP-44 (P2PKH, 1... addresses)
• Nested SegWit — BIP-49 (P2SH-P2WPKH, 3... addresses)
• Native SegWit — BIP-84 (P2WPKH, bc1q... addresses)
• Taproot — BIP-86 (P2TR, bc1p... addresses) with BIP-340/341 key tweaking
• Silent Payments — BIP-352 (static reusable address, sp1q...)
• Payment Codes — BIP-47 v1 reusable payment codes (PM8T...)
• Preview addresses — instantly verify the first 3 receive addresses for any wallet kind against Sparrow, Electrum, or hardware wallets

Extended Keys (BIP-32)

• Full HD key derivation from seed + optional BIP-39 passphrase (25th word)
• Extended public keys (xpub / ypub / zpub) for watch-only wallets
• Extended private keys (xprv / yprv / zprv) for full wallet import
• Live recomputation when the passphrase changes

Report & Encryption

• Plaintext report (.txt) — complete seed report with all entropy sources, derivation steps, extended keys, addresses, and reproduction instructions
• Encrypted report (.enc) — AES-256-GCM authenticated encryption with:
  • PBKDF2-HMAC-SHA-256 key derivation (600,000 iterations)
  • Random 16-byte salt + 12-byte IV per file
  • Binary format: AMLT header (4 bytes) + version (1) + salt (16) + IV (12) + ciphertext
  • Password strength meter with minimum 8-character enforcement
• Built-in decryptor — click the 🔓 icon in the header to decrypt any .enc file without external tools

Security & Privacy

• Zero-Telemetry Architecture — No analytics, no CDN imports, and no data ever leaves your machine.
• Connectivity Awareness — The tool uses the browser's native navigator.onLine status to warn you if the file is being opened in an online environment; it does not "phone home" or send requests to any external server.
• Single-File Portability — Every dependency (secp256k1, BIP-39 wordlist, Bech32/Bech32m encoder) is embedded inline.
• Memory wipe — one-click button zeroes seed data, keys, and cached values in the browser tab.
• Airplane mode guide — built-in instructions for going offline on macOS, Windows, Linux, iOS, and Android.
• Reproducible derivation — the report contains everything needed to independently verify the seed was generated correctly.
• WebCrypto API only — encryption uses the browser's native crypto.subtle, not a JS polyfill.

UI

• Dark and light themes with smooth transitions
• Responsive layout (works on mobile)
• Seed word masking (hide/show toggle)
• QR code–ready Bech32m addresses (uppercase alphanumeric mode)
• Floating back-to-top button
• Inline SVG logo and favicon (no external assets)

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Usage

1. Download amulet_1_3.html.
2. Disconnect from the internet (Airplane mode recommended).
3. Open the file in a clean, extension-free browser (or Incognito/Private mode).
4. Configure Seed: Choose between a 12 or 24-word mnemonic.
5. Enhance Entropy (Optional): In Advanced Mode, you can mix additional physical randomness into your seed using the Chaos Grid, Dice rolls, Random keystrokes, or Playing cards (recommended).
6. Generate: Click "Generate wallet".
7. Secure: Write the seed phrase on paper or stamp it into steel.
8. Export: Optionally download the plaintext .txt report or the encrypted .enc backup.
9. Wipe: Click "Reset and wipe all data" and close the tab.

For real funds: Always generate on a freshly booted, air-gapped machine. Never photograph or screenshot the seed. Use the "tails" operating system if possible.

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Verifying the Seed

Every report includes a "How to Reproduce Offline" section:

1. Take the COMBINED INPUT string (UTF-8, byte-for-byte)
2. Compute SHA-256 — result must match the report's hash
3. Take the first 16 bytes (12-word) or 32 bytes (24-word) as final entropy
4. Compute SHA-256 of that entropy — the first 4 or 8 bits are the checksum
5. Concatenate entropy bits + checksum bits, split into 11-bit groups, look up each in the BIP-39 English wordlist

This means you never have to trust Amulet — you can verify every seed it produces with any independent SHA-256 implementation.

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Encrypted Reports

The .enc file format is straightforward and can be decrypted with any language that supports AES-256-GCM and PBKDF2:

Offset  Length  Field
0       4       Magic bytes: "AMLT" (0x414D4C54)
4       1       Format version (currently 1)
5       16      PBKDF2 salt
21      12      AES-GCM IV / nonce
33      ...     Ciphertext (AES-256-GCM, includes 16-byte auth tag)

Key derivation: PBKDF2-HMAC-SHA-256(password, salt, 600000 iterations) → 256-bit AES key

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Standards Implemented

Standard	Description
BIP-39	Mnemonic seed phrase generation (English wordlist, SHA-256 checksum)
BIP-32	Hierarchical deterministic key derivation (HMAC-SHA512)
BIP-44	Legacy P2PKH addresses (m/44'/0'/0')
BIP-49	Nested SegWit P2SH-P2WPKH (m/49'/0'/0')
BIP-84	Native SegWit P2WPKH (m/84'/0'/0')
BIP-86	Taproot P2TR (m/86'/0'/0')
BIP-340	Schnorr signatures / x-only public keys
BIP-341	Taproot key tweaking (tagged hash)
BIP-173	Bech32 encoding
BIP-350	Bech32m encoding (Taproot)
BIP-352	Silent Payments (static reusable addresses)
BIP-47	Reusable Payment Codes v1

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Cryptographic Libraries

Amulet embeds the following (all MIT-licensed) directly in the HTML:

• noble-secp256k1 by Paul Miller — 4KB secp256k1 ECDH & signatures, RFC 6979 compliant
• BIP-39 English wordlist — full 2048-word array
• Bech32 / Bech32m encoder — constants 1 (Bech32) and 0x2bc830a3 (Bech32m)
• All other cryptography uses the browser's native WebCrypto API (crypto.subtle)

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License

MIT — see the license header in amulet_1_3.html.

Copyright (c) 2025–2026 AVB_21

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Disclaimer

This software is provided as-is. The authors are not responsible for any loss of funds. Always verify generated seeds independently before trusting them with real Bitcoin. We recommend working with software wallets on a safe machine, offline for optional verification.