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Does BIP39 mnemonic construction avoid repeating words?
Will all 24 words of a seed-phrase be unique by specification? Or is it possible for a word to occupy two positions (ie the word "tool" is #8 AND #20 in a valid, securely generated seed)
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2 Answers
There is nothing stopping a word to be repeated more than once. In a 24 word mnemonic, with 2048 possible words in the dictionary (BIP 39), there is a probability of at least one duplicate around 12.7% of the time (variation of the birthday paradox).
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No, the BIP39 construction does not avoid repeating words.
It is possible for a word to show up multiple times, but since there are 2048 words it is fairly unlikely for repeats to show up in randomly generated keys.
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Does BIP39 mnemonic construction avoid repeating words?
Will all 24 words of a seed-phrase be unique by specification? Or is it possible for a word to occupy two positions (ie the word "tool" is #8 AND #20 in a valid, securely generated seed)
4,6762 gold badges20 silver badges36 bronze badges
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There is nothing stopping a word to be repeated more than once. In a 24 word mnemonic, with 2048 possible words in the dictionary (BIP 39), there is a probability of at least one duplicate around 12.7% of the time (variation of the birthday paradox).
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