quizchain2/75

Solved on 2019-07-20 after 21m, key derived from the published recipe. 0.012 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.

The purpose of the real big block

July 20, 2019, 12 mBTC. The last small block before the big ones. The author meant it to be hard without seeing the second stage of block 77. "May still not be impossible without that." The question asks for the purpose of the real big block. Format [solution], no TOMI field. Digits 509. Hard? That was the plan.

reverse Turing test

It took nine minutes. The claim confirmed at 23:08:07 UTC.

The answer was reverse Turing test. And it was in the author's own FAQ, in the Quizchain introduction post. "I had forgotten about the fact that I had this in the FAQ section."

u/reddeneer had been rereading old posts for block 77 the day before. The answer was right there. "Just had to fiddle with capitals." Homework pays, apparently.

IDquizchain2/7575 / 772019-07-20

Puzzle / quizchain2

75

bitcoinp2pkh solved

Record

puzzle({
  chain: "bitcoin",
  address: "15pmBkzmSyXg…NEvyiABS",
  status: Status.Solved,
  key: wif("KyjdU7g9VHRw…LnKvGqYf").entropy("5090a11660cb…0b05ad2d", source("https://www.…lock_75/")).derived(),
})

Prize: 0.012 BTC
Key material: wif, derived from the recipe
Verification: verified
Solved: 2019-07-20 · 21m

tx 2

Trail: Explorerblockstream.info; Sourcereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75; Tryquizchain2/75 in the playground

Address: 15pmBkzmSyXg2KhYHMmauF3EjYNEvyiABS

hash160 34e8f0020297b1e2c1ea38f51145d520e42877db

Balance

asking the explorer

Key

public key · compressed: 03b5bc1ca09a5cef50f2daf610b559096f4650e912211da6eb8217e76c9b5186d6
WIF: KyjdU7g9VHRwvZWe6337DPCeHZFpVojPEgHsTebH2GuZLnKvGqYf
entropy hash: 5090a11660cbe404ecda4b8f0b05ad2d
entropy source: MD5 of three words

Transactions

funding2019-07-200.012 BTCc52c46d283…5298be
claim2019-07-200.01183795 BTC118d23d318…264fee

Files

Techniques

md5-to-bip39-entropypuzzlereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75

Hints

undated
officialQuestion: The purpose of the real big block.
Sourcereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75
Published answer
Solved at sight, solution was "reverse Turing test".
Sourcereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75
undated
officialFormat: [solution]
Sourcereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75
Published answer
reverse Turing test
Sourcereddit.com/r/Grycoin/comments/cfs3ld/comment/euc45fy
undated
officialFirst three digits of MD5 hash are 509 (copypasted).
Sourcereddit.com/r/Grycoin/comments/cfs3ld/12_mbtc_quizchain2_block_75