Unsolved
Bitcoin puzzle #72
Bitcoin puzzle #72 is unsolved. It holds 7.20 BTC, and its private key is an unknown number between 271 and 272−1 — a keyspace of 2.36 × 1021 possible keys. You can search that range with the solver below; it runs in your browser and never sends anything to a server.
Solver — #72
IdleJump to a random point in the range, sweep a block of keys, jump again. Best when many people search the same puzzle.
Each thread is one Web Worker on one core. Leaving a core free keeps the page responsive.
Walk the range in order from your start key up to the end of the range, splitting that region evenly across threads. Keys below the start key are not searched. Best when you are coordinating a systematic sweep.
Range covered: 0%
· Current key: 800000000000000000
Puzzle #72 at a glance
- Reward
- 7.20014379 BTC
- Address
- 1JTK7s9YVYywfm5XUH7RNhHJH1LshCaRFR
- HASH160
- bf7413e8df4e7a34ce9dc13e2f2648783ec54adb
- Range start
- 800000000000000000
- Range end
- ffffffffffffffffff
- Bit length
- 72-bit
- Keys in range
- 2.36 × 1021 (2361183241434822606848)
- Transactions
- 6
The arithmetic
The range for puzzle #72 contains 2.36 × 1021 private keys. A modern eight-core laptop running this solver checks on the order of four million keys per second, so an exhaustive sweep would take about 18.7 million years. Searching randomly instead of in order does not change that expectation — it only changes which unlucky order you fail in.
Puzzle #72 — common questions
How many private keys does Bitcoin puzzle #72 contain?
Puzzle #72 spans the range 2^71 to 2^72−1, which is exactly 2.36 × 10^21 private keys — twice as many as puzzle #71.
How long would it take to solve Bitcoin puzzle #72?
An eight-core machine running this browser solver at four million keys per second would need about 18.7 million years to sweep the whole range. A pooled GPU cluster reaching one trillion keys per second would need about 75 years.
How much is Bitcoin puzzle #72 worth?
The address holds 7.20014379 BTC, roughly $563,447 at a reference price of $78,255 per BTC.
Is Bitcoin puzzle #72 solved?
No. #72 is one of the 78 unsolved puzzles. Its public key has never been exposed, so square-root methods like Pollard's Kangaroo do not apply — brute force over the range is the only option.
What is the key range for puzzle #72?
From 800000000000000000 to ffffffffffffffffff in hexadecimal. The address is 1JTK7s9YVYywfm5XUH7RNhHJH1LshCaRFR and its HASH160 is bf7413e8df4e7a34ce9dc13e2f2648783ec54adb.