Anyone working with crypto probably has not just one, but several wallets. Different networks, different projects, different needs. It’s easy to reach 50 or more wallets if you’re really involved in the space. And each of them has its own mnemonic phrase.

Then comes the question many people ask: what are the chances of someone simply guessing my mnemonic phrase? It sounds scary, but let me explain how it works.

Most wallets use a 12-word mnemonic phrase. Some, like Ledger, offer 24 words. But here’s the detail: it doesn’t have to be that long. It’s all based on BIP39, a list of 2,048 words created in 2013 for Bitcoin wallets. This list is used by virtually all crypto wallets nowadays.

Now comes the interesting math. For the first word, you choose among 2,048 options. Okay. For the second, the combinations jump to 4 million. For the third, we’re already at 8.5 billion possibilities. You know that feeling of winning the Powerball? There’s a higher chance of that happening than guessing the third word of your mnemonic phrase.

When you reach the full 12 words, the number of possible combinations is a number with 39 digits. I’m talking about 340 quintillion possibilities. To give you an idea, there aren’t even that many atoms in the observable universe. So yes, it’s practically impossible for someone to guess your mnemonic phrase through brute force.

But there’s more. It’s not just about having the correct 12 words. You need them in the exact order. With state-of-the-art computers, it would take billions of years to test all combinations. It’s much more likely you’ll find your twin somewhere in the universe than someone cracking this.

That’s why a 12-word mnemonic phrase offers maximum security. There’s no real need for 24 words. Both provide 2 to the 128 security operations, so technically, adding more words doesn’t give you anything extra.

But mathematical security is only half the story. You need to protect your mnemonic phrase. Anyone who has access to it can access all your cryptocurrencies. That’s why many wallets also require a password, adding an extra layer of protection.

The safest way is simple: write your mnemonic phrase on paper. Not in digital format, not in a text file, not in an email. Paper itself. And not just one copy. Make at least two or three copies on different papers and store them in separate locations.

The problem is that paper burns, gets wet, becomes illegible over time. That’s why many hardware wallet manufacturers have created seed plates. Made of metal, fireproof, waterproof, impact-resistant, and practically indestructible. You can store up to 24 words on them.

If you were worried that someone could guess your mnemonic phrase, the answer is clear: no, it’s mathematically impossible. But real security depends on how you store and protect that phrase. That’s what really matters.