Bitcoin enthusiast cracks seed phrase made from known words in under 30 minutes

A user operating under the pseudonym Andrew cracked the seed phrase in under 30 minutes and won a reward of 0.001 BTC or about $29.

Thanks for dinner brotha!

Also… use 24 words people… ? pic.twitter.com/GtwgckSlqS

— Andrew (@dAnconiaMining) April 26, 2023

The competition was launched by Wicked, the creator of the educational Bitcoin account Wicked.

«Кто-нибудь хочет попробовать подобрать эту seed-фразу из 12 слов и получить 100 000 sat? Я дам все слова, но в произвольном порядке. Стандартный путь генерации, никаких ухищрений…», — подписал он изображение со словами и адресом.

A mnemonic phrase allows access to a Bitcoin wallet. It is a user-friendly representation of a large random number (entropy) that is used to generate Bitcoin keys. For constructing the phrase, 2048 predefined words from the English language are used.

Wicked noted that all 12 of the 12 known elements still yield 12^12, or about 479 million possible variant combinations.

Participants in the contest mostly commented on their attempts with little enthusiasm.

«Я пытался по меньшей мере шесть раз. Так расстраивает, что радует», — признался один из них.

I tried atleast 6 times. So frustrating its good

— BitcoinBoet (@BitcoinBoet) April 26, 2023

But a minute later, Andrew posted a screenshot of the found phrase and the withdrawal transaction with a signature:

«Thanks for dinner, bro! What else to say… people, use 24 words.”

According to Cointelegraph, the winner was a Chicago-based systems administrator, Andrew Fraser. He said that the crack, using the publicly available BTCrecover tool on his gaming GPU, took about 25 minutes. A more powerful system would have done it much faster, he noted.

He praised the initial security of a 12-word seed phrase provided that none of the words are known to an attacker, or if an additional passphrase is used during its creation. However Fraser reiterated his tweet, noting that a 24-word variant is best.

In 2020, Bitcoin investor Alistair Milne conducted an experiment to determine what volume of data is sufficient to crack a Bitcoin wallet. Developer John Cantrell gained access to a wallet with 1 BTC using 8 of the 12 mnemonic words.