b1000/81

b1000/81 unsolved bitcoin Bitcoin puzzle transaction

prize: 8.100015 BTC
key material: 81-bit search width
public key: unknown
started: 2015-01-15
solved: not yet
verification: puzzle has no private key

address · p2pkh

15qsCm78whspNQFydGJQk5rexzxTQopnHZ blockstream.info

hash160 351e605fac813965951ba433b7c2956bf8ad95ce

balance

asking the explorer

key range · 81 bits

2^80 to 2^81 - 1

0x100000000000000000000 to 0x1ffffffffffffffffffff

transactions · 4

funding2015-01-150.081 BTC08389f34c98c6063…1e5fa6cd15
increase2017-07-110.729 BTC5d45587cfd1d5b0f…4544384164
increase2023-04-167.29 BTC12f34b58b04dfb02…41a78d13b3
increase2025-10-140.000015 BTC3f83b6358b828308…68d302b9e2

source

open in the playground

https://bitcointalk.org/index.php?topic=5218972

toolpuzzles_show

what a model reads · MCP · Pi · OMP

b1000/81	unsolved	8.100015 BTC	15qsCm78whspNQFydGJQk5rexzxTQopnHZ
chain: bitcoin  address kind: p2pkh
hash160: 351e605fac813965951ba433b7c2956bf8ad95ce
public key: unknown
private key: unknown
started: 2015-01-15 18:07:14
transactions: 4
	funding	2015-01-15 18:07:14	0.081 BTC	08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15
	increase	2017-07-11 05:00:53	0.729 BTC	5d45587cfd1d5b0fb826805541da7d94c61fe432259e68ee26f4a04544384164
	increase	2023-04-16 06:29:48	7.29 BTC	12f34b58b04dfb0233ce889f674781c0e0c7ba95482cca469125af41a78d13b3
	increase	2025-10-14 12:07:24	0.000015 BTC	3f83b6358b828308e0e64bca18b727c0169636519ecb6643118c9a68d302b9e2
explorer: https://blockstream.info/address/15qsCm78whspNQFydGJQk5rexzxTQopnHZ
source: https://bitcointalk.org/index.php?topic=5218972
key range: 100000000000000000000..1ffffffffffffffffffff (hex, 81 bits)

puzzle.toJSON() absent fields are absent, never null

{
  "id": "b1000/81",
  "chain": "bitcoin",
  "address": {
    "value": "15qsCm78whspNQFydGJQk5rexzxTQopnHZ",
    "kind": "p2pkh",
    "hash160": "351e605fac813965951ba433b7c2956bf8ad95ce"
  },
  "status": "unsolved",
  "key": {
    "bits": 81
  },
  "prize": 8.100015,
  "start_date": "2015-01-15 18:07:14",
  "source_url": "https://bitcointalk.org/index.php?topic=5218972",
  "transactions": [
    {
      "tx_type": "funding",
      "txid": "08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15",
      "date": "2015-01-15 18:07:14",
      "amount": 0.081
    },
    {
      "tx_type": "increase",
      "txid": "5d45587cfd1d5b0fb826805541da7d94c61fe432259e68ee26f4a04544384164",
      "date": "2017-07-11 05:00:53",
      "amount": 0.729
    },
    {
      "tx_type": "increase",
      "txid": "12f34b58b04dfb0233ce889f674781c0e0c7ba95482cca469125af41a78d13b3",
      "date": "2023-04-16 06:29:48",
      "amount": 7.29
    },
    {
      "tx_type": "increase",
      "txid": "3f83b6358b828308e0e64bca18b727c0169636519ecb6643118c9a68d302b9e2",
      "date": "2025-10-14 12:07:24",
      "amount": 0.000015
    }
  ]
}