quizchain2/51

Solved on 2019-06-26 after 0s, key derived from the published recipe. 0.007 BTC on Bitcoin.

Story

What the post asked, what the answer turned out to be, and what the chain says happened. The record below holds the data.

No question

June 26, 2019. Block 51 has a format, [solution], and three digits, 4c4. No question. No TOMI field either.

The author funded it right before posting, with a high fee. The idea was to keep the window short, so nobody claims the prize before the post is even up. Smart. Did it help?

Eight seconds

Not really. Block 51, so 51 percent attack. u/DanTheDon83 saw it coming and had the answer written down in advance. u/JDScreesh timed the claim at eight seconds after the post.

The funding and the claim confirmed in the same block, at 23:04:41 UTC. Solve time on the chain: zero. The claim paid 16YUMnqAExU7yCCRaE1kfFrc4X9c4dMFjL, the address from blocks 44 and 45. A script for the claim? No, Electrum, said the winner.

Not everyone cheered. "Please go back to your puzzles", wrote u/mapl3sn0w, and asked for real ciphers again. The author promised a harder one next.

IDquizchain2/5151 / 772019-06-26

Puzzle / quizchain2

51

bitcoinp2pkh solved

Record

puzzle({
  chain: "bitcoin",
  address: "17EPFGMydd2s…1JGUHTVa",
  status: Status.Solved,
  key: wif("Kx5RaMi7KbKx…BZGkStyY").entropy("4c4cdbf69c62…400f8669", source("https://www.…lock_51/")).derived(),
})

Prize: 0.007 BTC
Key material: wif, derived from the recipe
Verification: verified
Solved: 2019-06-26 · 0s

tx 2

Trail: Explorerblockstream.info; Sourcereddit.com/r/Grycoin/comments/c5xj38/7_mbtc_quizchain2_block_51; Tryquizchain2/51 in the playground

Address: 17EPFGMydd2suYjbNShHrFYzj41JGUHTVa

hash160 4458bb708fb5bbc23f799577d5d7c1c16398fd6f

Balance

asking the explorer

Key

public key · compressed: 023b2309ea51d72b7147959bd21f5b90f185570e2dc4427420bd34f3e932f6cf5f
WIF: Kx5RaMi7KbKxouzMdEoszZDuGfLnn8aNEAx1xE8CJrsxBZGkStyY
entropy hash: 4c4cdbf69c62f3bf2dc68ab5400f8669
entropy source: MD5 of the number and two words

Transactions

funding2019-06-260.007 BTC424a3f6ba6…0d2eab
claim2019-06-260.00664634 BTC7eb9108818…5f0f5c

Files

Techniques

md5-to-bip39-entropypuzzlereddit.com/r/Grycoin/comments/c5xj38/7_mbtc_quizchain2_block_51

Hints

undated
officialFormat: [solution]
Sourcereddit.com/r/Grycoin/comments/c5xj38/7_mbtc_quizchain2_block_51
Published answer
Solution was simply "51 percent attack" and winner explained in comments that he already anticipated that, so the only time he needed was to run the Coleman tool.
Sourcereddit.com/r/Grycoin/comments/c5xj38/7_mbtc_quizchain2_block_51
undated
officialFirst three digits of MD5 hash are 4c4.
Sourcereddit.com/r/Grycoin/comments/c5xj38/7_mbtc_quizchain2_block_51