Interactive demo — progress through 6 sections to understand the concept
Generate random secp256k1 keypairs until the NPUB contains your chosen word. This is "vanity mining" — anyone can do it.
Here are two keypairs, both with "sat" in their NPUB. Anyone can make these. There's no way to tell them apart.
While we mine, here's how the scanner will evaluate each candidate. Two metrics, combined into one quality score.
The z-score measures how unusual a window is compared to random expectation.
Where σ (standard deviation) measures how much entropy normally varies in random windows. Here's how it's calculated:
Step by step:
A random 16-character window has ~3.57 bits of entropy on average, with σ=0.187. If we find one with only 1.5 bits, that's (3.571 − 1.5) ÷ 0.187 = z=11.1 — eleven standard deviations below the mean.
Higher z = harder for an attacker to replicate by chance. This is our anti-forgery metric.
A 16-character window with only 3 unique characters looks like:
A 16-character window with 10 unique characters looks like:
Same window size. Same z-score. But one is instantly recognizable and the other looks like noise. Fewer unique characters = bigger blocks of the same color = more recognizable to humans.
Logarithmic scale — like audio decibels. Every 10 dB is a 10× difference in raw quality. This spreads small values into a readable range:
The scanner optimizes for the highest quality score. This naturally selects patterns that are both rare (high z) and human-recognizable (few unique chars).
Mining started automatically when you entered this section. You don't need to press anything.
Now we scan the first NPUB from Section 2 with a multi-scale entropy scanner. We look for naturally-occurring low-entropy (repetitive) windows — outliers that were never designed, just discovered.
Alice's fingerprint (left) was discovered for free. An attacker (right) generates a new key with the same vanity prefix — but their fingerprint is completely different.
The complete identity system combines a human-readable vanity prefix (green zone) with the machine-discovered anti-phish fingerprint (orange zone).
A grinding service can find a vanity offset for your NPUB using ONLY your public key. It computes P + d·G for d=1,2,3... — never seeing your secret key.