quizchain/5

Solved on 2019-04-07 after 1h 40m, key published. 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.

Satoshi's words, letter for letter

The post asks "On this day ten years ago, how many bitcoins would you mine on average?" and skips the recipe: "if you don't know it, look at one of the previous "Quizchain" posts." So it's the same drill. Answer, the last three characters of the block 4 key, 6TX, SHA-256, entropy, m/44'/0'/0'/0/0.

It turned out harder than the author expected, so the first update adds a hint: "Answer needs to be in exactly the same format as Satoshi's answer to this question in 2009." The answer is a sentence, not a number. Satoshi wrote "Typically a few hundred right now." on bitcointalk, and exactly means the capital T and the full stop too. The string that derives the key is Typically a few hundred right now.6TX. Drop the period or put a space before 6TX and you get a different wallet.

The hint and the claim crossed

Funded at 11:08:39 UTC, posted at 11:11, swept at 12:49:32 for 643,500 satoshis. The second update says it plainly: "While I was giving this hint, someone has claimed the prize." The edit after it carries the solution and the WIF.

IDquizchain/505 / 772019-04-07

Puzzle / quizchain

5

bitcoinp2pkh solved

Record

puzzle({
  chain: "bitcoin",
  address: "1JR9yiCGuMrK…c5ZvXxK2",
  status: Status.Solved,
  key: wif("KwK9P8R81i3J…XKSwQKPb").entropy("c534df8925c3…1762e1d5", source("https://www.…block_5/")),
})

Prize: 0.007 BTC
Key material: wif
Verification: verified
Solved: 2019-04-07 · 1h 40m

tx 2

Trail: Explorerblockstream.info; Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5; Tryquizchain/5 in the playground

Address: 1JR9yiCGuMrKQ19pbt2GJudpv1c5ZvXxK2

hash160 bf0b9d9c4d25a5fc9f4541ecc1c9fb5bd69e65fb

Balance

asking the explorer

Key

public key · compressed: 020d091a1ea789d090a1b9f95a8bdf6b538f71749cc08eeb921cc84ba79a3eb3f9
WIF: KwK9P8R81i3JRFt5Ne7xT92hUxbAyKtkcxJcESd9x2rrXKSwQKPb
entropy hash: c534df8925c386ef2cad7502a427f478057357bc9210cb75e4845bd21762e1d5
entropy source: SHA-256 of Satoshi's sentence with the last three characters of the block 4 key appended

Transactions

funding2019-04-070.007 BTCff591de994…f4eb35
claim2019-04-070.006435 BTCb4d5865834…667491

Files

Techniques

sha256-to-bip39-entropypuzzlereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5

Hints

undated
officialOn this day ten years ago, how many bitcoins would you mine on average?
Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5Confirmweb.archive.org
Published answer
Satoshi answered this question on bitcointalk in 2009 like this: "Typically a few hundred right now."
Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5
undated
officialI skip explaining the format this time, if you don't know it, look at one of the previous "Quizchain" posts.
Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5
Published answer
Add last three digits of previous private key 6TX to claim the funds.
Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5
undated
officialAnswer needs to be in exactly the same format as Satoshi's answer to this question in 2009.
Sourcereddit.com/r/bitcoinpuzzles/comments/baf89m/easy_7_mbtc_quizchain_block_5