Cryptocurrencies use seed phrases, also called recovery phrases, as a sort of master password. If you have the seed phrase, you can restore your crypto assets even if you’ve lost access to your wallet — so if your hard drive fails or you leave your laptop at an airport, you don’t lose everything.
For most cryptocurrencies, seed phrases are generated from the BIP39 mnemonic code. Popular cryptos like Bitcoin use seed phrases with a length of 12-24 words.
Here’s an example of a BIP39 seed phrase (don’t get too excited — this code isn’t linked with any crypto asset).
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Below, we’ll answer a few of the most common questions we receive about BIP39 seed phrase security. To learn about our cryptocurrency data recovery services, set up a risk-free evaluation online or call us at 1-800-237-4200.
Can two people get the same BIP39 seed phrase?
Theoretically, there’s nothing to prevent two people from getting the same BIP39 seed phrase — it could happen. However, the chances of that actually occurring are exceptionally remote.
The BIP39 seed word list contains 2,048 words, so a 12-word seed phrase has about 2048^12 = 2^132 possible combinations, which is about 5.44 X 1039 in scientific notation.
That’s an impossibly large number: For comparison, the known universe contains an estimated 70 x 1023 stars, and there are about 75 x 717 grains of sand on Earth.
The total number of cryptocurrency wallets is insignificant compared to the number of possible seed phrases. Put simply, it’s virtually impossible for two people to receive the same seed phrase. You would have a much better chance of winning the lottery several times in a row.
What if someone tries to guess my 12-word seed phrase?
Using the math above, the number of possible seed phrases would translate to 132 bits of security. However, some of the words in a BIP39 seed phrase are not truly random.
Why? It’s complicated, but the BIP39 mnemonic code has rules to balance randomness with utility. Because of those rules, the actual security of 12-word seed phrases is 128 bits — which is still sufficient for protecting crucial data.
No current technology is capable of cracking 128-bit security. That may change in the distant future, which is why many cryptocurrency wallets use 24-word seed phrases. 24-word seed phrases double the security to 256-bits.
But generally speaking, you don’t need to worry about someone stealing your seed phrase — provided that you’re keeping it in a secure, offline location. Even if your seed is “only” 12 words, it’s still virtually impenetrable for malicious attackers.
If I have a portion of my seed phrase, can I recreate it?
It’s possible, provided that you have most of the words of your seed phrase.
Every word on the BIP39 word list is chosen to be identifiable by its first four characters, and certain words must appear in certain order. Once again, the mnemonic rules are outside of the scope of this article, but the bottom line is that a partial 12-word seed phrase may be recoverable under the right circumstances.
Logically, 24-word seed phrases are more difficult to “guess” from a fragment, but a professional data recovery firm can help you assess your options.
Datarecovery.com provides cryptocurrency wallet recovery services backed by our no data, no charge guarantee: If we’re not able to restore your funds, you don’t pay for the attempt.
To learn more, schedule an evaluation online or call us at 1-800-237-4200 to speak with a cryptocurrency recovery expert.