Generate passphrase
Each word comes from rolling five fair dice (1–6) and looking up the five-digit code in the official EFF list. Twenty words yields 258.3 bits of entropy — above the 256-bit target. Demo mode: rolls below use server CSPRNG — see comparison with physical dice.
CSPRNG vs physical dice
Why server rolls are statistically fairer — and why you should still use real dice for production secrets.
Verify physical dice rolls
Enter your own dice rolls (five digits 1–6 per word, one word per line).
Example: 42653 16233 … or comma-separated groups.
This is the path EFF recommends for secrets you actually intend to use.
Cosmic scale proof
Exact combinatorics with BigInt — how a 20-word passphrase compares to the physical universe.
More combinations than the Eddington proton estimate — comparable to every atom in the universe
7776^20 = 2^258.50 = 6.53 × 10^77 combinations
✓ beats all sand on Earth
✓ beats every star
✓ beats Eddington estimate
✓ ≥ 2²⁵⁶ key space
≈ same scale as ~10⁸⁰ atoms
| Reference | Scale | Ratio | |
|---|---|---|---|
| ≈ | Atoms in the observable universe | ~10⁸⁰ | 15.3× |
| ✓ | Eddington number (1930s proton estimate) | ~1.6×10⁷⁷ | 4.1× |
| ✓ | 256-bit private key space | 2²⁵⁶ ≈ 1.16×10⁷⁷ | 5.6× |
| ✓ | Stars in the observable universe | ~10²⁴ | 65.3 million× |
| ✓ | Grains of sand on Earth | ~10²² | 6.5 billion× |
Brute-force proof: Guessing every combination at 1 billion per second would take 2.07 × 10^60 seconds — about 1.49 × 10^51 times the age of the universe.