quizchain2/21

Solved on 2019-05-29 after 1d 11h 33m, 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

May 28, 2019. The question asks if you can solve a block without any question. Cute. The format wants a TOMI field, and the post gives the first digit 72e and nothing else.

Players went straight for the paradox. No Question TOMI No. without question. liar TOMI because it contains a question. All of them fit the first digit, and none of them fit the hash.

u/silver_anth wasn't amused. A question should have one answer, they said, and a TOMI field just to make it harder is "wrecking this quizchain". The author disagreed and kept the field.

The block number

A day later came the hint: "You know only the block number." Then a nudge. Might 21 mean something in the Bitcoin space?

Of course it does. 21 million, the coin limit. The TOMI field is three lower case words, fixed money supply. After that hint it was just a race for the TOMI field.

The claim confirmed at 23:06:39 UTC on May 29. u/silver_anth won and said sorry to everyone who spent hours on it. u/JDScreesh guessed 21 million and got lost in the TOMI. English isn't their first language, and TOMI fields don't care.

u/puzzleponky had the best take afterwards. The block wasn't hard because of TOMI. Everyone just looked in the wrong direction, and a tiny nudge would have been enough.

IDquizchain2/2121 / 772019-05-28 → 2019-05-29

Puzzle / quizchain2

21

bitcoinp2pkh solved

Record

puzzle({
  chain: "bitcoin",
  address: "145XVhfc2hbP…5EZ9gTKq",
  status: Status.Solved,
  key: wif("L3Pg58Hf7C15…4h4GAVXM").entropy("72e49243678e…eadfed34", source("https://www.…lock_21/")).derived(),
})

Prize: 0.007 BTC
Key material: wif, derived from the recipe
Verification: verified
Solved: 2019-05-29 · 1d 11h 33m

tx 2

Trail: Explorerblockstream.info; Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21; Tryquizchain2/21 in the playground

Address: 145XVhfc2hbPxtkQbB9VKyjigA5EZ9gTKq

hash160 21c37f3c5e2388df604c5c4bec61f5156be8e46e

Balance

asking the explorer

Key

public key · compressed: 03029fb4e3bc3bbaffa36e95b7441c9f24051cae196b7d37c70d1cf4d89b7d67c0
WIF: L3Pg58Hf7C15Bmy8ejYsKk2AyfmJQeR5826bc3piGRVj4h4GAVXM
entropy hash: 72e49243678e88024aa76afeeadfed34
entropy source: MD5 of the number, TOMI and three words

Transactions

funding2019-05-280.007 BTCe7c7fa6c81…fe6bee
claim2019-05-290.00653449 BTC7935256020…3db9ec

Files

Techniques

md5-to-bip39-entropypuzzlereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21

Hints

undated
officialQuestion: Can you solve this block without any question?
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
Published answer
The solution was obviously 21 million (the limit on the number of bitcoins), which reduced the task to finding the TOMI field. I chose "fixed money supply" for that.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
undated
officialFormat: [solution] TOMI [TOMI]
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
Published answer
solved: 21 million TOMI fixed money supply
Sourcereddit.com/r/Grycoin/comments/bu6umc/comment/epdq8m4
undated
officialFIrst three digits of hash are 72e.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
undated
officialUpdate: First digit of solution only MD5 hash is 9.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
undated
officialFirst digit of TOMI field only MD5 hash is f.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
undated
officialYou know only the block number.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21
undated
officialMight the number 21 be significant in the Bitcoin space somehow? Oh, and TOMI field is three words in lower case.
Sourcereddit.com/r/Grycoin/comments/bu6umc/7_mbtc_quizchain2_block_21