SLIP39 KeyTag Dotmap

A comprehensive solution that converts SLIP39 mnemonic words into physical dot patterns, for use with OneKey KeyTag hardware backup devices. This project provides a complete reference documentation for secure, offline wallet backups, as an alternative to the official OneKey KeyTag BIP39 dotmap.

Security Notice

This project is designed for air-gapped, offline usage to prevent exposure of sensitive cryptographic material. SLIP39 mnemonics control cryptocurrency funds, always use offline methods when working with seed phrases.

Warning

There is a saying in the cryptocurrency world: The words seed phrase and keyboard should never appear in the same sentence.

• Always use air-gapped devices, never enter real patterns into electronic devices
• Create multiple copies stored in separate secure locations
• Verify accuracy, incorrect dots mean lost funds

Methodology

SLIP39 (Shamir's Secret Sharing for Mnemonic Codes) provides enhanced security over BIP39 through threshold secret sharing, allowing you to split your seed into multiple shares where only a subset is needed for recovery. This dotmap implementation enables you to store SLIP39 phrases on durable metal OneKey KeyTag hardware backup devices, providing:

• Compatibility - Works with existing OneKey KeyTag hardware backup devices
• Physical durability - Resistant to fire, water and electromagnetic pulses
• Threshold security - 2-of-3, 3-of-5 sharing schemes vs single point of failure
• Offline storage - No digital attack surface

Key Differences

Aspect	BIP39	SLIP39
Word Count	2048 words (indices 1-2048)	1024 words (indices 1-1024)
Security Model	Single seed phrase	Threshold sharing (M-of-N)
Dot Usage	All 12 dots used	11 dots used (leftmost always empty)
Recovery	Need complete phrase	Need threshold number of shares

Usage

The process involves converting SLIP39 words to their corresponding dot patterns for physical storage, and later recovering the original words from the punched patterns.

Dotmap Generation

Equipment needed:

• OneKey KeyTag hardware backup device
• Printed SLIP39 conversion table

Steps:

1. Look up each word in the conversion table
2. Mark corresponding dots on your KeyTag hardware backup device
3. Verify patterns match the reference exactly

Dotmap Recovery

Method 1: Scientific Calculator (Recommended)

Equipment needed:

• Scientific calculator with binary/decimal conversion (e.g., Casio fx-991ES PLUS C)
• Printed SLIP39 conversion table

Steps:

1. Enter BASE-N Mode: Press MODE → Select BASE-N
2. Switch to Binary Mode: Press SHIFT → Press log (Bin)
3. Read KeyTag pattern: Convert ○ = 0, ● = 1
4. Enter 12-bit pattern: e.g., 000000001111 → Press = to execute the input
5. Convert to decimal: Press SHIFT → Press x² (Dec)
6. Look up word: Use result as SLIP39 word index

Examples:

• Pattern ○○○○○○○○●●●● → 000000001111 → 15 → advocate
• Pattern ○○●○●●●●○○●○ → 001011110010 → 754 → result

Method 2: Manual Calculation

Equipment needed:

• Basic calculator
• Printed SLIP39 conversion table

Steps:

1. Identify bit positions: [2048][1024][512][256][128][64][32][16][8][4][2][1]
2. Add punched positions: Sum all ● positions
3. Look up word: Use result as SLIP39 word index

Examples:

• Pattern ○○○○○○○○●●●● → positions 8 + 4 + 2 + 1 = 15 → advocate
• Pattern ○○●○●●●●○○●○ → positions 512 + 128 + 64 + 32 + 16 + 2 = 754 → result

Physical Layout

The OneKey KeyTag hardware backup device provides 12 positions, arranged in 3 groups of 4:

[2048] [1024] [512] [256] | [128] [64] [32] [16] | [8] [4] [2] [1]

Important

For SLIP39, the leftmost 2048 position is always empty (○). This is correct behavior, not an error.

Examples

Word #15 advocate → 8 + 4 + 2 + 1 = 15

Physical: [2048] [1024] [512] [256] | [128] [64] [32] [16] | [8] [4] [2] [1]
Pattern:   ○      ○      ○     ○       ○     ○    ○    ○      ●   ●   ●   ●

Word #754 result → 512 + 128 + 64 + 32 + 16 + 2 = 754

Physical: [2048] [1024] [512] [256] | [128] [64] [32] [16] | [8] [4] [2] [1]
Pattern:   ○      ○      ●     ○       ●     ●    ●    ●      ○   ○   ●   ○

Technical Details

For hands-on learning and practice, see the interactive SLIP39 KeyTag Converter web application. The following formula was used, to build the SLIP39 conversion table:

function calculateDotmap(index) {
  // Convert index to 12-bit binary
  const binary = index.toString(2).padStart(12, '0');

  // Split into 3 columns of 4 bits each
  const bits11to8 = binary.substring(0, 4);
  const bits7to4 = binary.substring(4, 8);
  const bits3to0 = binary.substring(8, 12);

  // Convert binary to dotmap (● = 1, ○ = 0)
  function binaryToDotmap(binaryStr) {
    return binaryStr.split('').map(bit => bit === '1' ? '●' : '○').join('');
  }

  return [
    binaryToDotmap(bits11to8),  // Column1
    binaryToDotmap(bits7to4),   // Column2  
    binaryToDotmap(bits3to0)    // Column3
  ];
}

This ensures mathematical consistency and unique representation for each word, while maintaining compatibility with existing OneKey KeyTag hardware backup device.